Hmm. REALLY not understanding circulation

None of this, however, takes away from your nice way of presenting in a
simplified way, why it is that the air speeds up over the top of a wing.

I'm probably driving everyone who understands this crazy by now, but I'm
still not getting it. Every time I think I am, I challenge myself to explain
it to myself, and I fall down at the same point. And the point is ~still~
why the air speeds up over the wing at a positive angle of attack, and gets
faster as the angle of attack gets greater.

I grasp the concept that higher speed leads to lower pressure. That is
settled.

What is eluding me is the reason why the pressure is lower above the wing. I
answer it by saying "the air is faster", but that brings me back to the
question: "why does a wing oriented at an angle of attack make the air go
faster?". Obviously I can't answer it with "because it lowers the pressure",
because that would just cause me to ask "why does it lower the pressure?"
which we would be answered by "because the air is going faster", which gets
me back to the start. This is the short-circuit in my understanding at the
moment.

Roger's description here seems to make sense to me:-

http://www.avweb.com/news/airman/183261-1.html

"Since the wing is at an angle, its movement also tries to sweep out a space
behind the top. The inertia of the air that goes over the top of the wing
tries to keep it moving in a straight line, while the pressure of the
atmosphere tries to push it down towards the wing's surface. The inertia
prevents the atmospheric pressure from packing the space as firmly as it
would if the wing were standing still. The result is a low-pressure region
above the wing. Air rushes from high- to low-pressure regions, from the
high-pressure area ahead of and below the wing into the low-pressure space
being swept out above and behind it."

...... as does this:-

http://www.allstar.fiu.edu/aero/airflylvl3.htm

"So how does a thin wing divert so much air? When the air is bent around the
top of the wing, it pulls on the air above it accelerating that air down,
otherwise there would be voids in the air left above the wing. Air is pulled
from above to prevent voids. This pulling causes the pressure to become
lower above the wing. It is the acceleration of the air above the wing in
the downward direction that gives lift."

Are these enough to rely on to give a broad overview of what is going on
above the wing?

I actually think I do understand a fair bit of the stuff "downstream" of
this point. I'm pretty sure that once the above concept clicks into place.

Thanks in advance. I hope I'm not making anyone head butt their keyboards in
frustration.