The most fundamental error that we all make is assuming we can understand what it feels like to be inside someone else’s mind and heart.

It’s not a conscious decision to believe this. It’s just a natural assumption we start with to one extent or another. But the more I’ve become aware of this error — first by observing myself and then by observing and re-interpreting others — the more aware I’ve become how pervasive it is.

What’s worse, I’ve realized that almost all of the manipulators in our lives use this assumption to control us.

Imagine you are locked alone in a bare cell with a locked door. You can’t see anyone else. You can’t hear anyone else. You have no idea where you are or why you’re there. You just know you’re alone.

Now imagine you become aware of other people elsewhere. Let’s say you and some other people start tapping on the walls or maybe water pipes running through the rooms. You slowly develop a primitive system by which you feel as though you’re communicating simple thoughts through these taps.

The more you tap — and the more the responses to those taps meet your expectations — the more you feel confident that you understand what other people are saying. You can’t experience them directly, but you create meaning in your head and then modify that meaning depending on what those taps seem to say in response to your taps.

That is exactly what each one of us does in real life.

I am trapped inside my own head and heart. You are trapped within your own head and heart, too. You have never had the opportunity to experience what goes on inside my head. It’s impossible for me to experience what goes on inside your head or your heart.

But as we started learning things as small children, we started making assumptions about the world and then we started making assumptions about other people. Without realizing exactly what we were doing, we started assuming that other people’s internal experiences were much like our own.

The more I understand about myself and about other people, the more I conclude that this assumption is fundamentally mistaken. I’ve come to believe the experience in my own head is radically different from the one inside your head.

I’ve also come to realize that most people are so attached to the meaning they assign to everything in their own heads — what experiences mean and feel like, which thoughts and feelings are “normal,” and what someone else should think and feel — that they judge you for deviations from their own internal meanings. Then they manipulate you by preying on whatever fears you have come to experience in your own thoughts.

There are all sorts of ways in which people do this. For instance, let’s say you experience something which pushes your emotional buttons for some reason and upsets you greatly. You might not even fully understand why the experience makes you feel as you do, but your feelings and actions feel completely normal to you — based on your lifetime of experiences and assumptions.

Let’s say you feel as though there’s a danger that someone around you isn’t taking seriously. Let’s say that something in your past has programmed you to be deathly afraid of losing someone or scared of a particular kind of danger. If that were true, you might react to a small danger in a way that seems excessive to someone else.

In such a case, a manipulator has no interest in understanding why you’re feeling as you are or acting as you are. He wants only to control you. So he tells you that you’re crazy, maybe. He knows you are afraid — either because of general social attitudes or personal experience of some sort — that you’re afraid of being perceived as crazy.

“You’re just crazy,” the manipulator says. “You’re acting irrationally. You need to be more like me — if you don’t want me to think you’re crazy.”

A manipulator always has a way to control you. He might say you’re too sensitive. He might say you’re lazy. He might say that “everybody knows” some particular thing.

Such a person doesn’t even necessarily know what he’s doing, because he truly assumes that others feel as he does inside and that “normal” people will think and feel and act as he does — because he honestly assumes that what happens in his own mind and heart is the proper standard for what’s normal.

I can never come inside the prison cell of your mind. You can never come inside my own. The best we can hope for is to learn to communicate as clearly and effectively as we can — questioning our assumptions and trying hard to understand what each other is thinking and feeling. If you and I can start with the understanding that we can’t objectively understand each other — and if we can reach out to try to understand what the other thinks and feels — we can have a basis for some understanding.

At the very least, we can quit manipulating each other and trying to force each other to adopt the thoughts and feelings which we are certain must be objectively correct.

We reach a point with some people that we no longer have enough trust to even try to communicate or understand. When the pain of attempting to interact with someone is too much — and there’s no hope that anything is going to change — complete separation can be the only thing to save one person from slowly learning to hate the other for not being able or willing to give what that person needs.

The bad news is that we’re each trapped inside private prisons of our own and we have no way of bringing anybody inside our cells.

The good news is that we have the ability to work with others we choose to understand more about our differing assumptions and about what someone else really feels.

The best news is that real love and connection can bridge those prison cells if two people who trust each other make the decision to make it happen.

Those who end up alone in their cells — with no love connecting them to someone else — will die miserable after unhappy lives. Those who make loving connection with someone else can experience a kind of joy that comes in no other way.

Every single one of us has to make that choice for himself or herself. Perhaps no other choice of life matters more in determining whether our lives are fulfilling and happy or solitary and miserable.