Thanks, vessbot I got it now, but my flight school instructor clearly hadn't all those years ago
At the time, it did not seem likely to me that a wing and a propellor worked in completely different ways.
Regarding the air "wanting to get from A to B" and why it does this above and below; remember the air is static, and the aerofoil is moving through the static air.
So the air molecules are not trying to get anywhere, they are just sitting there, having a great time, when this hulking great wing or propellor blade suddenly whizzes past them. As it goes by, the molecules near the upper or forward surface are squeezed together more than the ones underneath/behind.
I guess this lower pressure makes the air above move downwards towards the wing, and then continue downwards over the back edge, resulting in a large mass of air being "pushed" down.