Because (as a group), the more we have, the more we want.Someone sleeping on the street might only want a warm soft place tosleep, but another person making a six-figure salary might want tobe richer so that they can afford to buy a home in Manhattan. Thereis no point at which most people just stop and say that they haveeverything that they need and couldn't possibly want anythingelse.People don't even know what they want, but they feel empty andwant more... meaning, or stuff, or love, or health, or popularity,or whatever it is. There is always something you can do to improveyour life, and so there is no end to what people will want.