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.

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.

Few of us can accurately gauge how we will feel tomorrow or next week. That's why when you go to the supermarket on an empty stomach, you'll buy too much, and if you shop after a big meal, you'll buy too little.

The secret of happiness is variety, but the secret of variety, like the secret of all spices, is knowing when to use it.

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.

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

Our inability to recall how we really felt is why our wealth of experiences turns out to be poverty of riches.