When we think about happiness, we usually think of something extraordinary, a peak of great delight--and those peaks seem to get rarer the older we get. For a child, happiness has a magical quality. I remember making hide-outs in newly cut hay, playing cops and robbers in the woods, getting a speaking part in the school play. Of course, kids also experience lows, but their delight at such peaks of pleasure as winning a race or getting a new bike is unreserved. For teenagers, or people under twenty, the concept of happiness changes. Suddenly it's conditional on such things as excitement, love, and popularity. I can still feel the agony of not being invited to a party that almost everyone else was going to. But I also recall the great happiness of being invited at another event to dance with a very handsome young man. In adulthood the things that bring great joy--birth, love, marriage--also bring responsibility and the risk of loss. Love may not last, sex isn't always good, loved ones die. For adults, happiness is complicated. My dictionary explains happy as 'lucky' or 'fortunate', but I think a better explanation of happiness is 'the capacity for enjoyment'. The more we can enjoy what we have, the happier we are. It's easy to overlook the pleasure we get from loving and being loved, the company of friends, the freedom to love where we please, even good health. Nowadays, with so many choices and such pressure to succeed in every area, we have turned happiness into one more thing we 'gotta have'. We're so self-conscious about our 'right' to it that it's making us extremely unhappy. So we chase it and consider it to be the same as wealth and success, without noticing that the people who have those things aren't necessarily happier. While happiness may be more complex for us, the solution is the same as ever. Happiness isn't about what happens to us--it's about how we perceive what happens to us. It's the ability to find a positive for every negative, and view a setback as a challenge. It's not wishing for what we don't have, but enjoying what we do possess. According to the author, happiness lies in the ability to ______.