I remember this one distinctly because in school they just gave me a handout and asked me to come up with the explanation myself. I thought about it. I didn't know. It seemed like if you had an angle of attack then the air would hit against the bottom -- like a knife would want to continue to travel straight through a fluid. I didn't know what the significance of the curve over the top of the wing was. They tried to guide me toward the equal-transit-time explanation and I was like, uh, ok, is that really true? I remained suspicious of this for a long time.