Quote from intervention:
Yeah but don't you think there must be a level where we start to enjoy the things we have achieved by so much hard work. Or just keep working more and more to earn more but enjoy less !
Enjoy, of course. But work more and more too if the process is what we enjoy as well.

People have different motivations. I seriously doubt those who make billions do it because they need it in life. Rather it's the process of the competition itself what makes them excited, so they keep doing it.