I always wondered why people can devote so much time and effort into their hobbies. After all, to an outsider, it all seems just like a big waste of time. But after observing some of the hobbies, I've come to a conclusion that the hobbies that allow you to inject your own creativity and create something are the ones that's most addictive and time consuming. In Warhammer, players get to assemble and paint their own army. For Magic: The Gathering, you get to design and pilot your own decks. Hobbies like these gives you the opportunity to accomplish something.
I think in general, all of us have this need to create something of our own, be it in your working life or your leisure time. As a programmer, I can fulfill this need by coding applications. For those that feel they can't accomplish or create something in their career, they might seek to do this in their hobbies instead.
The best case scenario for this would be to be able to create something and make a living out of it. That is basically what entrepreneurs do. If you can somehow align your need to create with the demands of others, you got yourself a business right there.