Apparently, contrary to general perceptions, old people are happier, and get happier as they age.
"When people start out on adult life, they are, on average, pretty cheerful. Things go downhill from youth to middle age until they reach a nadir commonly known as the mid-life crisis. So far, so familiar. The surprising part happens after that. Although as people move towards old age they lose things they treasure—vitality, mental sharpness and looks—they also gain what people spend their lives pursuing: happiness."
So the bad news is if you are heading towards middle-age, things may get a whole lot worse before looking up again. The good news however, is that it will get better!