Long before my art lessons stopped around age sixteen, I knew I would never be a professional artist. Partly, this was just a milder incarnation of other children's realizations that they would never be, say, Major League Baseball players. But the real turning point for me came with the onset of puberty and its accompanying compulsive self-analysis. I realized that I owed what success I had as an artist not to any specific art-related aptitude, but rather to a more general and completely orthogonal skill.
Drawing what you actually see—that is, drawing the plastic bull that's in front of you rather than the simplified, idealized image of a bull that's in your head—is something that does not come naturally to most people, let alone children. At its root, my gift was not the ability to draw what I saw. Rather, it was the ability to look at what I had drawn thus far and understand what was wrong with it.