I don't fly fish, but I do hang around with someone who does. He swears he catches things, although I've never seen it myself, despite the two of us having been out more than a few times!
He seems to spend more time whipping the thing over his head than with the lure in the water. Maybe I'm missing the point, but I always thought you'd have more luck with the lure in the water where the fish are than whipping through the air where fish generally don't congregate.
Def