Falling is simply flying from a different perspective. There just happens to be a very large, inevitable wall in your way
The pertinent quote on flying as falling is here.
Actually, the line struck me after reading
Ender's Game because I was thinking a lot about shifting perspectives in a zero-gravity environment as well as my own shifting emotional perspectives.
But yeah, Adam's description of flying as falling is wonderful. What was the name of the story that Escape Pod published about the boy who fell into flying? I thought that was one of the more interesting and touching character studies that EP has done so far.