In many movie, just like the Se7en-an American film, human beings are always greedy, they never satisfied with what they already have and always want more. However, not everything goes like that, although indeed people are chasing more beautiful dresses or a greater achievement dispite they are almost perfect.
It is human's nature that they want a better life. So people never fail to unstisfied and a great deal of man are working hard to earn more money so that they can buy a bigger house or an expensive roadster. As well, some women dreaming to marry a  millionaire so that they can buy more beatiful dresses, shoes or Famous-Brand perfumes. Take an extreme case, Big S, one of most sucessful actresses in china, once said, she have more than five hundred shoes and his shoe cabinet is large engough for three people to sleep there, but she is still desair to buy more in oreder to make a own museum of shoes.
The unsatisfy is more common for althelet. In each new Olympic game, there always some one break the record. And every year, innumerous althelet are training hard to get better record of themselves. Liu Xiang, for example, a famous hurdle althelet is still training hard to run faster today although he had ever broken the world record of hurdle in 2006.
Dispite all these instance that human beings never get enough, people always feel satisfied in some aspects just like a happiness family or a loving spouse. Rarely does people who has a gracious father and a goodness mother in a harmonious family want more father or mother. Also for a couple who really love eachother, neither of them may want more wife or husband in affection.
In conclusion, although human beings are greedy in some stuff like clothes or  achievement, with a happiness family, people always feel satisfied in their love.