Twenty-five years ago, economist Tibor Scitovsky explored some of the consequences of the phenomenon of adaptation in his book The Joyless Economy. Human beings, Scitovsky said, want to experience pleasure. And when they consume, they do experience pleasure--as long as the things they consume are novel. But as people adapt--as the novelty wears off--pleasure comes to be replaced by comfort. It's a thrill to drive your new car for the first few weeks; after that, it's just comfortable. It certainly beats the old car, but it isn't much of a kick. Comfort is nice enough, but people want pleasure. And comfort isn't pleasure.