Awesome quote: "It was a shock to realize that my teacher and even the library books could be wrong. And it was a revelation that I could trust my own thinking in the face of such concerted opposition."
Nonsense. Everything is wrong until proven otherwise. The burden is on the presenter to justify the statement. The moment doubt is raised then the presenter must address it. Someone pointing out a logical error in the presenter's assertion is not required to come up with some other explanation in order to explain that error.
Of course if they do they are held to the same standard.
There are many crackpots that 'have been shocked to realize that library books and teachers were wrong and that they should trust their own thinking in the face of concerted opposition'. Only slightly different from the original, but the italicized words make a world of difference. Einstein's (special) theory of relativity faces scores of opponents that 'trust their own thinking', despite not having a single fact that casts doubt on it.
Flat wings work with a positive angle of attack (EX: paper airplane). The problem with scaling this up is turbulence at the sharp edge. A gently curved surface reduces turbulence and drag. Remove enough turbulence and you get a laminar flow which hugs both sides of the wings. You can deflect a laminar flow down to increase lift. (See faucet experiment.) Control surfaces on the wing redirect the flow to push the aircraft in a new direction. Incresing the angle of attack increases lift until you reach the critical angle of attack ~15 degrees when you lose laminar flow and a sudden drop in lift occurs. Stall speed is the speed below which you can't maintain level flight by increasing angle of attack. High performance aircraft and trade efficiency for performance (EX: an F-15 landed after losing a wing http://www.uss-bennington.org/phz-nowing-f15.html)
Super sonic flight behaves somewhat differently. (See faucet with increased pressure.)