I'm a gamer, and I really like to think of myself as a game creator too, even if I haven't made much that's worth playing outside of a Starcraft map.
(I've made hundreds of playable maps, though)

Like a lot of people, I spend a lot of time at my computer. So I have, of course, accumulated a lot of knowledge about computers in general, which is relevant and helpful in my endeavors to create and test video games.

Also I've done large amounts of image creating/editing with PSP, I've done some C++ programming, and I've used with Game Maker a bit as well.