I remember being in my lesson, one of the first I had on Red. I was on the lunge line and as we went trotting by the rail a cat jumped down from the hayloft onto the rail of the arena (which was a frequent occurrence). That sounds odd but if you knew the set up of that arena it makes more sense... Anyways, the cat landed practically right in front of Red's face, he jumped right, and I tumbled right over his left shoulder. No injuries at all, just scared the bejeezus out of my 10 year old self.
Needless to say there have been DOZENS of falls since then and although I don't have evidence of the first one, I do have evidence of one. It's seriously a surprise I don't have more...
Scroll to around 0:50 to see my dismal riding ;)
And then you can enjoy this photo of me nearly falling off my horse. Despite jumping 3ft. cross country courses like a badass, she periodically stopped at plain cross rails. For funsies.