Field
What is taught wrongly
Equal transit time, Bernoulli misapplied, and the rest. Each stated fairly, then tested against a solved flow and found false.
The story about air meeting up again
The most repeated explanation of lift says that air parting at the nose must rejoin at the tail, so the longer upper path forces a higher speed. The premise is false, and the speed it predicts is wrong by a factor of twenty.
Where Bernoulli's equation applies
The equation is right. Its hypotheses are strict, and almost all misuse is a correct formula carried somewhere it does not hold — across streamlines, through a fan, or into the one layer where friction is the whole story.