Riding with a -very- lovely woman. Watching her -very- lovely spandex covered backside. Not noticing the the road curved sharply to the left.
I landed in several inches of muck and leaves in the bottom of the drainage ditch alongside the roadway. I had just long enough to think, "Wow...not a scratch on me. I wonder where my bike is?" Then it hit me. Square on top of me. Hard.
Paul