What's the worst fall you ever had?

My worst fall happened when I was cantering a pony up the hill to our outdoor arena. He took off with me, I stayed on for a little bit but then ended up falling off and hitting my head HARD. I ha d a concussion and cracked my helmet. I hit my head so hard that a large chunk of my helmet broke off. It was scary and awful. I don't remember anything about the rest of that night...