My husband and I were out riding in the pasture with a good friend about 10 years ago before we owned our own horses. He was riding a very quiet 20 year old Tennessee Walker and I was riding our friend's 7 year old, 18 hand Percheron gelding that she raised from a baby. The pasture we were riding through backed up to a subdivision, separated by a line of trees. In one of the houses behind the trees, a couple of guys were playing basketball in the backyard, and the noise of the bouncing ball echoed up the hill to where we were. All three horses went on edge - you have to admit, it's a bizarre noise!
We decided to turn the horses around and head to a different part of the pasture and in doing so, my gelding lost sight of his "mom" - and bolted. I remember asking him to stop, and apparently, he did exactly as I asked. I, however, kept right on going and hit the ground head first. I remember nothing after that until I woke up with a paramedic standing over me as they loaded me into the ambulance. The doctors told me after looking at my CT scans that had I not been wearing a helmet, I likely would never have woken up at all. I ended up with a concussion and a sprained shoulder, but I'm still here to keep on riding, and have since gotten my own horse. I ride 3-4 times a week, but never without a helmet!