I'm a competitive person at heart. If I honestly can't beat someone/something while playing to the best of my ability, I start getting aggravated, and usually won't let it rest until I figure out AT LEAST the why aspect. For this reason, I find myself logging on Starcraft 2 just for the co-op vs AI games. Not only because it's easy, but I don't have to worry about my rating, or countering new strategies that come out. It also is a really easy way to enjoy the actual game, while still being able to hold a normal conversation with someone, beit in-game, or on Ventrilo/Skype.