Also the rider's age is not a problem. In London Olympics the oldest participant was a Japanese dressage rider, years. Youngest rider was probably And where your "equipment" can choose not to cooperate with you
"I don't care if your trip was a shoe-in for champion, or you got disqualified at the first fence. You walk out of that ring, pet your horse and thank him for not killing you because you know damn well he could have.