The younger a person is, I have found, the more they think they know themselves. They can be heard, saying things like, “I’m not like this, I’m like that… I never… I always… my personality is…”

They limit themselves this way.  That’s what I did.

The older I get, the more I surprise myself. I find myself doing things I never thought I could.

I’ve taken up many things later in life, never knowing that I would like them, never knowing I would be any good at it.

Ten years ago, I never played tennis. I thought it was an effete sport, with fussy clothes, and incomprehensible scoring. Watching it gave me a pain in the neck. Servile ball boys scurried around and tried to make themselves disappear. Then, one day, I played it with my nephew. I could barely hit the ball, but I had fun. I took lessons. Now I play twice a week and hit the ball well. I even figured out how to keep score. Much of the time, I win.

I like that there are things I might still discover. It gives me some options.

Why do we think we know ourselves before we do?

It happens this way:

A boy grows up with an older brother who always beats him at basketball.

Despite the fact that the older brother is older, bigger, and stronger, the boy assumes that he is not good at athletics because he always loses at basketball.

Because all siblings find their niche, the boy becomes a bookworm. He excels at school.

The boy grows up to go to Harvard because he thought he was good at school. There, he plays Ultimate Frisbee in Harvard Square between classes. Because he is not playing with his older brother, but other bookworms, he discovers he’s a good athlete.

He goes home for vacation and, for the first time in years, he plays his older brother at basketball. He beats him.

We come to conclusions about ourselves by comparing ourselves with others. How we think about ourselves depends on who we compare ourselves to, who we meet, who we get to know.

Each new person we meet, each new situation we are in, brings out a new part of us. When we limit ourselves, we never meet any new people, we never try new things. The more we think we know ourselves, the more we don’t.