Layman's guess: wings push air down, air pushes wings up.
An everyday experiment is sticking your flat hand out the window of a moving car. With slight wrist rotations, you'll find even slight deviations from neutral (parallel to the ground) cause your "wing" to rise or fall, with a force that seems proportional to the angle.
We can hypothesize that a symmetric wing, with zero angle of attack, should experience no lift:
An everyday experiment is sticking your flat hand out the window of a moving car. With slight wrist rotations, you'll find even slight deviations from neutral (parallel to the ground) cause your "wing" to rise or fall, with a force that seems proportional to the angle.
We can hypothesize that a symmetric wing, with zero angle of attack, should experience no lift:
https://aviation.stackexchange.com/a/35139