I've always said, money is a pleasant side-effect of intellect intersecting with passion, work ethic, and a bit of luck.
Once you find that intersection that works for you, you won't give it up. The thrill of executing your strategy is intoxicating. Like imposing your will on an entire marketplace. There's no drug like it.
I love what I do. I don't do it for money, though it has made me wealthy. But I hardly find time to spend my wealth. I simply accumulate it, and am at times amazed at what it's doing all on its own with very little help (tip: exchange traded funds with low management fees can be your friend if you're a lazy bastard and spend all your time working to make money instead of how to invest).
Now, I simply work for the love of what I do. It's become like an old friend to me. We push each other, challenge one another, let each other down, pick each other up, and surprise each other with amazing things. Each day is new, and though I don't always have all the answers, I know I'll probably find them because I'm better than most of my competition at what I do.
And when I do find answers, I make money. Lots of it. It's really quite amazing how easy it is to make money off people if you know a little bit about what you're doing. It's not like the millionaires out there are all Rhodes Scholars. Most are just guys and girls who took a shot, got a bit lucky, and stumbled into something sweet. Now, if you can be halfway smart and calculating and planful about what you do, you can get rich in a hurry.
But it won't be about money then. Then, it'll just be about the thrill of the hunt to take down the next challenge, best another opponent, and do something you hadn't done yesterday. It's a drug...there's no other way to put it.