The Economist reports on The U-bend of life and asks: Why, beyond middle age, people get happier as they get older?

The answer amounts to little more than a confirmation of American philosopher William James's pithy observation:

How pleasant is the day when we give up striving to be young—or slender.

Indeed, striving may be the central concept. It also explains the reason citizens living in countries that place a very high premium of social equality (such as Denmark) seem happiest.