This is an excerpt from The Pathfinder: How To Choose or Change Your Career for a Lifetime of Satisfaction and Success, written by Nicholas Lore and published by Simon & Schuster.

Nearly everyone has difficulty turning their most passionate dreams into reality. Usually, when this happens, we blame the circumstances or ourselves. Most of us can imagine ourselves doing work that fulfills everything important to us. Yet, when we step out of the realm of fantasy and attempt to forge a life that is a major improvement on our current situation, we fall prey to doubts and difficulties. In this chapter you may discover the culprit that keeps some parts of our lives going around and around in the same old groove. The next few pages present a model of how our brains work when we seek to expand our lives into new territory. This is a useful interpretation, not the one and only truth. Looking at your life from this perspective can give you a greatly enhanced ability to have your life turn out the way you want it to. In particular, it will help you whenever you are taking a giant step into the future. You do not need to suspend your beliefs about how your mind works. If you think your ego keeps your id from going farther than baying at the full moon, fine. Since this is just a useful model, it doesn't matter if it is the truth or not. What does matter is whether or not this model helps you be more resourceful in actually living a life you love. Let's take a look.

Take a look at the illustration entitled Chart of a Life. It is a record of someone's satisfaction as they go through life. It could be a chart of satisfaction at work, love life, or any other aspect of life. At the bottom of the scale, below 20%, life holds no real satisfaction. You are in the pits. Things seem about as bad as they could be. At the top, above 80%, you are completely in love with life. No matter what happens, you see the bright side. When you discover that your wonderful new lover is an ax murderer, you think, "Yes, but he's so good at it."

Consider your satisfaction with any part of your life in relation to this scale. Let's say your satisfaction in love relationships usually hovers around 50% on the scale. Your love life is OK but not great. Then something happens that drives your level of satisfaction down to 10 or a 20%. Unlike Humpty Dumpty, it does not take all the king's horses and all the king's men to put you back together again. It just takes time. Sooner or later, you will find yourself back at the good old 50% level again. Rarely do people stay deep in the pits for long. Somehow they find their way back to their usual level of satisfaction. They may change partners to get back to 50% or they may work things out in their existing relationship. They will do anything to return to their usual, customary level of satisfaction. It is not 100%, it's not 90% but it is what they are used to. Like a thermostat, we seem to be set for a certain "temperature" of satisfaction.

What happens when a miracle occurs and your love life really takes off? Your relationship flourishes or you fall in love. Suddenly, you find yourself on cloud nine. In this state of bliss, even washing the dishes can feel like dancing through fields of flowers. Life has become perfectly satisfying. You have soared to 90 to 100% on our chart. Will it last? Will you live happily forever after? Of course not. Either you will slowly drift back to 50% or you will somehow screw it up so you land with a thud back at 50%. You may sincerely want to have a very satisfying love life. It could be something you strive for, work for, care about deeply. But you keep winding up at good old, same old, predictable 50%. Why?

Right now, you may be asking, "What does all this have to do with choosing a career?" Nothing at all if your life, your work is as deeply fulfilling as you'd like it to be. Nothing at all if you are willing to leave your life to the ebb and flow of circumstance. If you plan to have a deeply satisfying career, one that goes beyond the ordinary level of satisfaction and success most people accept, then it may be worth noticing that there seems to be a mechanism at work that tends to keep people stuck to the same spot on the flypaper of life. The better you are at unsticking the stuck, the more power you have to say how your life will be.

Look at the illustration called, "Equilibrium." It looks like a seesaw that is balanced in the middle, because no one is sitting on either end. Let's use it to demonstrate how minds work. Don't worry for now about the little things under the ends of the seesaw. We'll get to them in a minute.

Living things naturally return to a state of balance. When they are disturbed by forces acting on them, our inner machinery kicks in and returns us to a balanced state of equilibrium, just like this seesaw. Homeostasis is the word we use to describe the ability of an organism to maintain internal equilibrium by adjusting its physiological processes. Most of the systems in animal and human physiology are controlled by homeostasis. We don't like to be off balance. We tend to keep things at an even keel. This system operates at all levels. Our blood stays the same temperature. Except for extraordinary exceptions, when people find ways to intervene using methods more powerful than our tendency to equilibrium, our habits, behaviors, thoughts and our quality of life stay pretty much the same too. We say, "I'm in a rut." or "I'm stuck in the same old groove."

Every time something in our lives gets out of balance, our internal machinery sets off behaviors designed to return us to equilibrium. In the illustration called "Out of equilibrium," the things under the ends of the seesaw are switches. You can see that when balance is disturbed, the seesaw tips a little bit one way or the other and it pushes one of the switches. Pushing one of the switches sets off a behavior designed to return you to equilibrium. Notice that no matter which way the seesaw moves, it sets off one of the switches. So, whether your life has hit the skids or is on cloud nine, powerful forces of homeostasis are at work to return you to equilibrium.

To understand how this tendency to return to equilibrium controls our lives let's look back to an earlier time, a time when reptiles and amphibians were number one on the evolutionary hit parade. Imagine a frog sitting by a pond. It's a wonderful, sunny day. Everything is perfect. The air is filled with a veritable feast of delicious flies. All of a sudden the frog notices something large moving nearby. Instantly, it jumps into the pond. What's happening here? Why does it leap? It does not think, "Look at that evil looking thing heading my way. Maybe I should make myself scarce." It doesn't really think about it at all. Its equilibrium is disturbed and it just reacts. Look at the Illustration called "Reptile Brain." And please, don't get upset because a frog is technically an amphibian and the illustration says "Reptile Brain." They are both the same except that, if you were to visit an amphibian neighborhood, you would notice that everyone has a pool in their back yard.

The frog is happily humming along on idle dreaming of things that only frogs can imagine. All of a sudden its equilibrium is disturbed. The seesaw tips. That sets off a switch and the frog reacts. It leaps into the pond. It leaps for its life. Not like you, you say. You make carefully thought out conscious choices, you say. Let's imagine you are in town one day. As you cross Main Street, you are dreaming of things only you can imagine. You hear a noise and look to your left. A bus is a few feet away, rushing at you at 60 miles an hour. What do you do? Will you stop to carefully consider the philosophical implications of your plight? No, you're going to do exactly what the frog did. You will leap out of the way. You'll make a mighty leap even if you haven't recently brushed up on your leaping lessons. This reaction to a disturbance is hard-wired into your brain. The part of your brain that helps you leap out of the way of the bus is not much different from the part of the frog's brain. All of this takes place in a very ancient and primitive part of your brain.

There's not much you can do to alter or train some of these hard-wired survival mechanisms. There are very few frog trainers listed in the yellow pages (except in California) because you can't train a frog. A frog is basically a sophisticated survival device, programmed, like all of us, with various features designed to increase its odds for survival. Most of the time, it exists in a condition of equilibrium. When it perceives a potential threat to its survival, it reacts. Its reaction really has nothing to do with its external circumstances, it is reacting to regain equilibrium.

The most basic strategy of the process of evolution is to increase the odds for survival. One of the really giant advances in evolution was the invention of high tech, advanced mammals. Surrounding the ancient reptile brain, nature built a new brain, a powerful new generation of software with advanced features and extraordinary new survival abilities. See the illustration "Mammal Brain."

One of the mammals' most amazing advancements was a greatly increased ability to learn from experience. They could add to their mental software. They could develop specialized survival strategies that made them much more flexible in responding to new environments, conditions and threats.

A horse ambles contentedly through a field, nibbling at the delicious tips of long oat grasses. Suddenly a lion attacks. The horse wheels and dashes to escape, only inches in front of the flashing claws of doom. It runs for its life. Forever afterward, whenever anything, such as a field of long windblown grasses, reminds it of that threat to survival, it instantly becomes more alert. The memory of the earlier event drives it out of equilibrium and into a survival reaction - super-keen alertness. It doesn't analyze what happened. It simply reacts to regain equilibrium. It has learned to handle a new kind of threat.

If you think about it, whenever you are out of equilibrium, off balance, you are in a state of reaction. If you had a few angry bees buzzing around your head, you would likely be in a state of upset, reacting by having all of your thoughts focused on your bee problem. If someone, at that moment, asked you "What's the capitol of Albania?", your brain would be completely unavailable to deal with that question. You would be totally focused on the bees. So, being in a state where you are out of balance may be useful for dealing with the current emergency but it narrows your ability to deal with other things. Evolution has developed a brilliant solution: the habit.

If you were one of Mother Nature's engineers, charged with improving the design of mammal survival devices, you would try to find some way the animal could come face-to-face with reoccurring threats and deal with them successfully without getting so upset that it was incapacitated. That's exactly what nature does. After the mammal repeats something a few times, it becomes a habit. A habit is an automated reaction designed to keep you at equilibrium while, at the same time successfully dealing with a threat. Habits get the job done without all the upset. The horse learns to stay away from the tall grass. When it must travel near tall grass, it becomes more alert without getting completely knocked out of equilibrium. Whatever strategy it used successfully to survive becomes the standard mode of operation rather than a reaction that is only triggered when there is a threat. It is no longer upset. It has learned. Horses take the same path up the hill, time after time. They are creatures of habit, predictable. Much of what you and I do comes from this mammal part of our brains. We too are creatures of habit. The first time I drove a car on a narrow two lane road, the cars whizzing by in the other direction seemed like a huge threat to my survival. Every ounce of my attention was concentrated on them. After a few days' experience, I paid no conscious attention to them. Once anything has become a habit, we don't have to pay attention to it anymore. The rub with this elegant piece of survival machinery is that, generally speaking, we are governed by our habits. When we are not aware that our lives are run by pre-programmed software, it becomes very difficult to captain our own ship.

The development of our human brain was another major transformation in the evolution of intelligence. One of the new features nature gave us is our ability to project ourselves into situations that haven't happened yet. You and I can stand on a hilltop, look out across the landscape and think, "You know, it looks to me like that could be a field where lions might hang out." When we imagine walking through the field and being attacked by lions, we feel fear, have a surge of adrenaline and decide to go another way. This design feature gives us an enormous survival advantage. We can imagine potential threats without having to actually experience them.

Consider this: You come out of the movie theater and discover that it is pouring rain. A dark alley runs back along the side of the theater. You realize that you could save two blocks getting to your car if you cut through the alley. As you consider taking the short cut through the alley, you imagine muggers hiding in its shadowy recesses. You feel a chill of fear just thinking about it. You decide to stick to the safer, well-lit main street. What is happening here is that you get yanked out of equilibrium just thinking about walking through the alley. Unlike the horse, you don't have to get mugged to learn.

So, we possess an extraordinary survival advantage. But along with the benefits comes the biggest problem faced by people who wish to create anything new in their lives. The big problem is that the most advanced human parts of our survival systems operate exactly the same way the reptile and mammal parts do. If something throws you out of equilibrium, your homeostasis machinery reacts automatically. The design function of these systems on all levels, from the human part of your brain down to the ancient primordial parts of it, is survival. All the parts of your survival system defend your physical body from harm as they do for the horse and the frog. See the illustration called "Human Brain."

We humans have a lot more than our bodies to defend. Therein lies the source of the difficulties we have in making our most passionate dreams come true. We have an identity. We see ourselves as separate from the rest of the world. Way back there in prehistoric times, when you were hairier and your forehead was half an inch high, your ability to create concepts, to distinguish yourself from your environment, led to having an identity independent from your body. This is what we commonly refer to as the "ego." Your ego or identity is flexible. It changes from moment to moment, from situation to situation. It is not as simple as "ME Tarzan. You Jane." To Tarzan, there is more than one Tarzan to identify with. There is Tarzan the King of the Jungle, Tarzan the wonder-filled naive English Lord. There is Tarzan the lonely, lovesick guy, Tarzan the clever hairless ape, and so forth.

The human part of our survival system is designed to defend our identity as well as our body. Any time there is even a hint of a threat to the survival of our identity, we are instantly thrown out of equilibrium into an automatic survival reaction. Since we have multiple identities, the system defends whomever or whatever we consider ourselves to be at that moment. Sometimes this works in our best interests. Sometimes it doesn't.

Let me offer a couple of examples. Where I live, a high speed beltway goes around the entire city. When they built this super highway, there was an area filled with people so rich and powerful that they had to build the road around their neighborhoods. So the usually straight road got as curvy and dangerous as a ski run full of moguls. Of course, everyone drove at about 75 miles per hour. There I was zipping along with everyone else, listening to tunes when I hit the curves. Next to me, in the lane to my right, was a propane truck. On my left was a huge shiny enamel black Peterbilt eighteen wheel tractor trailer with "The Nitro Express" lettered in flames on the door. And as we all roared around the corners together, my sunglasses, resting on the dashboard, skittered across the dashboard to my right. What did I do? Without thinking, I reached to the other side of the car to save the sunglasses and in doing so risked my own life. When I thought about it afterwards, I realized that, for that moment, I had become my sunglasses. All that existed in my entire universe was the sunglasses. My survival system was willing to sacrifice my life to save "me," the sunglasses.

In medieval Japan, a samurai warrior's identity was his honor. In the code of Bushido, maintaining one's honor was more important than anything, including life itself. So if something happened that besmirched his honor, what did he do? He committed ritual suicide. And if he died well, which in that system of beliefs meant he was supposed to look pretty cool on the way out and not allow the pain and horror to show, he regained his honor. Good system, huh? Unfortunately, nobody noticed that there was one small fly in the ointment. The samurai wasn't around to enjoy the fact that he had survived. But losing his life was a small price to pay to regain his honor. His identity survived. Our highly sophisticated survival system isn't intelligent. It doesn't care if the samurai lives or dies so long as his identity survives. Your survival system does not care about your happiness. It does not care whether you have wonderful, satisfying relationships. It certainly doesn't care if you have a fulfilling career. Sometimes it doesn't even care if your body survives. It's just a bunch of mechanisms running on automatic; and mechanisms don't care. Mechanisms don't think, they react.

Most of the time we don't think that we are our sunglasses or our honor. We usually think we are who we have been. If you woke up in the morning, looked in the mirror and there was someone else's face staring back at you, it would be an enormous shock. We usually consider ourselves to be that familiar character we have known all of our lives. Good old, same old you. You who likes certain things, thinks and behaves in certain unique ways. You who won second prize in the a cappella yodeling contest. Good old, same old you who has these strange things happen in your love life. If your survival system protects your identity at all costs, it will react if something seems to threaten your identity. It will do almost anything to keep everything the same.

If the quality of your love life hovers at around the middle of the satisfaction scale, your survival system will do all it can to return you there if you stray. If everything falls apart, your survival systems will kick in until you are back at equilibrium, the good old, same old middle of the scale. If you find yourself heading toward the top of the scale, in a state of romantic bliss, it will be interpreted as a threat to the survival of your identity. It knows you do not belong in paradise. Sooner or later, you will find yourself back in the middle. In most areas of life, the return to the accustomed region is as fast as the survival system can propel you there.

Your survival system will defend who you have been in the past, in regard to your career. If your work experience has been a fully successful, profoundly satisfying experience so far, the survival system will go all out making sure it stays that way. If you have been doing work that isn't highly satisfying, guess what? It will work just as hard to defend the status quo, no matter how much you wish it wasn't so. If you are a young person without much work experience, you are not exempt from the system. It also depends on how you look at life: your personal philosophy, opinions, point of view and beliefs. That's why women who believe that all men are pigs always seem to find themselves with piggy guys. If somehow you made up or absorbed and accepted certain rules about work or anything else, your system will make sure your life continually validates your rules.

The frog and the horse react physically to threats. The human part of our brain has another less direct but equally effective way to run from danger, the "Yeahbut." When you think about taking the shortcut through the dark alley, your mind thinks, "Yeahbut, I might get mugged." Whenever you consider stepping into unknown territory in any area of your life, you will develop a case of the Yeahbuts. The simple act of seriously entertaining the thought of expanding your life drives the system out of equilibrium which triggers a survival reaction, a massive attack of the Yeahbuts.

Don't turn the Yeahbuts into a new enemy. Ninety percent of the time they, like the other parts of your survival systems, are your ally. If you are dancing at the edge of the Grand Canyon, the Yeahbuts warn you of the danger. Remember, without the Yeahbuts, you would have taken the shortcut through the alley. We are designed to be at equilibrium most of the time. People who are usually out of equilibrium are stressed and prone to disease.

Yeahbuts become your opponent only when you seek to add new dimensions to your life, to take a giant step. When you intend to create something new in your life, the survival system interprets movement toward that goal, or even serious speculation about going after such a goal, as a threat to the survival of your good old, same old identity and launches a Yeahbut campaign to get you back to good old same old equilibrium. As soon as you consider committing yourself to an improvement in the quality of your life, your system is thrown off balance and the Yeahbuts begin. Think of it as a mental auto immune disease. The salient point is that most of us have very limited skills in successfully intervening in the automatic, mechanical functioning of these systems.

Different people have various degrees of hair trigger. Some people can dream endlessly about possible futures and stay in a state of equilibrium. It is only when they start making commitments or plans that they get attacked. Other people have only to begin to vaguely entertain wisps of thought of something new to trigger an attack of Yeahbuts as massive as the attack on Pearl Harbor.

The Yeahbuts are so effective in getting you back to equilibrium because they are very persistent. They are not intelligent. They just don't give up until you are back at even keel again. Like a persistent fisherman, the system tries out different lures until it finds one that snags you. Anyone who has ever quit smoking or given up any long standing habit knows exactly what I mean. At the most vulnerable moment, the little voice says, "Hey, have a puff to remember what it tastes like. It won't hurt. I'm in control. I can stop when I want. After all, I'm out with my buddies. I'm having a beer. I always used to have a cigarette when I had a beer. They go together perfectly. It would taste so good right now. I'll only smoke one." It's a very, very powerful force because the system keeps trying new lures until one of them hooks you.

There are endless Yeahbuts that get in the way of choosing and creating the perfect career. Here are a few of my own personal favorites:

• I'm too young, too old, too stupid, too smart.

• I'm the wrong gender. The wrong color.

• I didn't/ don't/ won't have the right opportunities.

• I have lots of energy and stick-to-itiveness. It's just soooo difficult to decide what to do. If only I could decide.

• I'm constrained by my circumstances, my mortgage, my bad back, no time. The circumstances are like a vice around me, holding me here. I can't do anything about it.

• I don't have enough will power. I'm not a risk-taker.

• I'm not committed enough. I have this habit of quitting.

• I couldn't do anything I would really want to do.

• I'm really trying. It's not my fault. Really!

• I don't have enough money. I don't have enough talent.

• I can't do what I want because the fun careers pay less.

• I'm sensitive, an artist. I couldn't possibly have a regular job because I see through the banalities of crass materialism.

• I want to help people, but this is a cruel, heartless world where only the lawyers win.

• It takes putting my shoulder to the grindstone, year after year, and that's not my style.

• It's hopeless. I have this fatal flaw. It's my karma.

• I'm an immigrant. My English isn't good enough.

• I should have been born in an earlier time.

• I don't have the courage to go out and push and make cold calls and do the things that I need to do to get that kind of job I want.

• I'm over- or under-educated, over- or under-qualified, have too much or too little experience and all the experience I have is really a detriment because it's in the wrong field.

• I just got out of college. They didn't teach me what Shinola is anyway.

• I went to the wrong college, didn't have enough college, didn't go to college, got a degree in an area that is completely useless in today's market place.

• My skills are antiquated, they're outdated, under rated.

• What makes me think I can decide now, when I have failed to for all these years?

Like all of us, you probably have some others besides these little gems. They are the lyrics to the song the townspeople's chorus sings in the old opera, "It's Not Fair." What kind of an opera is it? Hint: It's something you use in the shower.