The first time I fell off was when I was taking a private lesson when I first started riding- I might have been seven or eight. The mare I was riding either spooked or I did something to cue her without realizing it [this is too long ago for anyone who was present to remember] and she took off. I went flying. Wasn't hurt, just scared out of my mind!
The next three falls all happened off the first horse I showed. He was the slowest, laziest horse you ever met, and I probably would've done better in Western Pleasure classes then in my English classes, but regardless. He spooked at any small thing, and twice he spooked in a corner of the indoor arena. Directly outside was the mare's pasture, so I'm sure they were acting up and he heard and spooked. I slid right off both times and had the wind knocked out of me but again was not hurt.
The third time with the same horse was out on trails. There were two horses in front of me, and the middle horse was trying to go down this little hill.
|__________ < It looked like this. Literally, a tiny hill, but the horse kept getting upset over it. His nervousness made my horse nervous and the first horse nervous, and while the other two were trying to fix things out, my horse spotted a deer that was on the trail ahead. He spooked, I slid off, and that was that. Being young, we all dismounted, too scared to continue riding, and walked home. No injuries.
The next time was off of Rainy, my current horse. I was putting her over a few 8 inch cavalettis when she [and I suspect she was frustrated, since we had been working for a while, and I was pushing her to continue, rider error 100%] reared up and bolted. I was off before she bolted, but still no injuries. According to my friend who was riding with me at the time, she was perpendicular to the ground.
Time after that, my girth came loose and I bailed, rather than being thrown/falling off. After that, I was on trails and she spooked [I wanna say it was a deer] and bolted off.
Finally, the last time I fell off, we were cantering in the outdoor arena and she lost her footing. It had sprinkled eariler, but the ring seemed fine, so I went ahead and rode outside like an idiot. Her back legs slipped out from underneath her, so I threw my weight forward to help her get her balance. Instead, her front legs slipped out too and my weight going forward nearly pitched myself over her head. Then I lost my balance too and we both fell to the left. Luckily she jumped right back up so she wasn't laying on top of me. I was slightly bruised, but no major injury.
I've been pretty lucky. For the amount that I've fallen off, I've never been seriously hurt. *knock on wood* :)