If someone offered you a pill that would make you permanently happy, you would be well advised to run fast and run far. Emotion is a compass that tells us what to do, and a compass that perpetually stuck on north is worthless.

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.

In short, if we adhere to the standard of perfection in all our endeavors, we are left with nothing but mathematics and the White Album.

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.

Part of us believes the new car is better because it lasts longer. But, in fact, that's the worst thing about the new car. It will stay around to disappoint you, whereas a trip to Europe is over. It evaporates. It has the good sense to go away, and you are left with nothing but a wonderful memory.

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.

People want to be happy, and all the other things they want are typically meant to be a means to that end.