[MattAMiller]

One really must wonder why these people can't just be happy. They're fabulously rich, they're doing exactly the kind of work they want to do, they get to be creative, they get to travel the world and meet all sorts of interesting people. Most people can only dream of such a life. So why do they never seem to be able to appreciate it? What's with all the looney behavior?

[wimpycat]

I think these people aren't happy precisely because they get everything they want. They don't have much to strive for. They aren't "hungry" anymore.

Evidence of this phenomenon on a much smaller scale: I really love music. I used to dream about the day I would be able to afford whatever records (now CDs) I wanted. Now that I can, and have, bought most of the CDs I wanted, it's just not the same anymore.