Shoot, if I had no debt and a guaranteed income of $25,000 a year (without working, because I do have a lazy streak) I could be happy. Just knowing I could wander all over the world, live a year here, a year there... I mean, it’s my version of happiness, which is rather solitary, Spartan, and weird, but ... that’s all it would take.
What happens is that would get old, and then what would be your next enjoyment. Most people spend their whole lives focusing on maybe 3-4 things. If rich, the problem still exists as the focus is different, but still runs out.