The mistakes we make when we try to imagine our personal futures are also lawful, regular, and systematic. They, too, have a pattern that tells us about the powers and limits of foresight in much the same way that optical illusions tell us about the powers and limits of eyesight.

The data says that with the poor, a little money can buy a lot of happiness. If you're rich, a lot of money can buy you a little more happiness. But in both cases, money does it.

Research suggests that people are typically unaware of the reasons why they are doing what they are doing, but when asked for a reason, they readily supply one.

Impact is rewarding. Mattering makes us happy.

If I wanted to know what a certain future would feel like to me, I would find someone who is already living that future. If I wonder what it's like to become a lawyer or marry a busy executive or eat at a particular restaurant, my best bet is to find people who have actually done these things and see how happy they are.

Psychologists call this habituation, economists call it declining marginal utility, and the rest of us call it marriage.

I have everything that I could possibly want in life, from a gorgeous granddaughter and a wonderful wife, brilliant students, the best job anyone could hope for, and about half of my hair. Not the half I would have kept, but no one consulted me.