The eye and brain are conspirators, and, like most conspiracies, theirs is negotiated behind closed doors, in the back room, outside of our awareness.

Your emotions are meant to fluctuate, just like your blood pressure is meant to fluctuate. It's a system that's supposed to move back and forth, between happy and unhappy. That's how the system guides you through the world.

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.

If you are like most people, then like most people, you don't know you're like most people.

I actually think the same things do make most people happy. The differences are extremely small, and around the margins. You like peach ice cream; I like strawberry ice cream. Both of us like ice cream much better than a smack on the head with two-by-four.

When we have an experience -- hearing a particular sonata, making love with a particular person, watching the sun set from a particular window of a particular room -- on successive occasions, we quickly begin to adapt to it, and the experience yields less pleasure each time. Psychologists call this habituation, economists call it declining marginal utility, and the rest of us call it marriage

Lower your cortisol level. The happiest people have the lowest level of cortisol, a stress hormone that raises blood pressure and weakens the immune system. Cut the stress-more yoga, less road rage-and you'll cut your cortisol production.