Not only that, you can actually fly on just one aileron (pylon guys do it intentionally, us combat guys do it once in a while not-so-intentionally). The one aileron will roll the plane in both directions.

I'll second the idea that it's important to know your "theory" of how the various bits work to make an airplane fly in a controlled manner. With out that understanding, it's easy to make mistakes and not get things like the old "up elevator make the plane go up, more up elevator makes the plane go DOWN" thing. (I once actually saw a guy fly straight down in to the ground and say "I must have been hit, I was holding full up the whole way down, but the plane just didn't pull out").