Money makes you happy.
I've gone from utterly broke to living pretty well the past few years. But I actually really miss the old days. I earn more because I invest more time in constructive projects, and have far less leisure time than I have.
Also, when you earn well and buy stuff, it doesn't mean so much. A few years ago, buying something like a TV or stereo would have been a big deal, and I'd spend really carefully. I found myself getting careless with my spend - ie, just buying, instead of researching first, and didn't like getting burned for it.
Overall, money is just wallpaper on the walls of life - whether I'm living in a 4 bed house or a run down caravan, I'll make sure I'm happy regardless of money.
2c...