I can't remember my first one, but the earliest one I can remember I was about 4 (read feet didn't reach the stirrups and I had no lessons or anything before) walking around the small yard outside of a big pasture.
Someone went to open the gate and the mare took off towards it. The idiot operating the gate did not see the mare making a break for it.
I jumped off. And tore the hot pink sweatpants I was wearing