" It is said that humans are never satisfied, that you give them one thing and they want something more. And this is said in disparagement, whereas it is one of the greatest talents the species has and one that has made it superior to animals that are satisfied withe what they have. "
-The Pearl by John Steinbeck
I guess that we should have things we want to improve on, but let us not get too greedy and want things in excess all the time. :)