Eeyup, I learned most of mine by playing Unreal Tournament '99, Diablo, and the first Sims, so came time when I took classes in school, I already knew most of the stuff.
I usually play through games with similar qualities to get a feel for the mechanics orfeatures that I would love to include. I'm currently playing through Muramasa: The Demon Blade (Mostly for the hand-drawn artwork), Metroid: Zero Mission (The massive world to explore), and LittleBigPlanet (the awesome physics the game incorporates) :D