There's nothing wrong with your behavior. Everyone acts this way. You don't have any kind of compulsion. And it's normal to feel satisfied with what you have and normal to want other things, as well. It's just a desire to acquire material things once in a while then come to the realization that you really don't need them. That's rational thinking, imo. If you couldn't stop buying material things and run up huge credit card bills that might be a compulsion.