There is a woman, in mid 40's now who is a quad. Been that way for around 30 years.
When she was 16, she went out to where the family horse's were standing under some trees, she got on her mare with no tack, not even halter/lead rope.
Horses decided to take off. She fell and broke her neck and has been paralyzed ever since. Horses were all gentle and laid back, and she'd been riding for over 10 years at that point too.
I guess my question would be is...why would you want to take the risks?
Horses make me a better person.