Two kids who had never wrestled before came out for the team when I was in junior high: Jeff and Dave Alexander. They were twins, and they were gymnasts. I watched them each do over a hundred, with good form... they quit, it seemed, more because it was getting boring and annoying than because they couldn't do more. Dave, eventually, went back to gymnastics, and did well in college; Jeff stuck with wrestling, and was a state finalist for us twice.
It should be noted, though, that when they did this, they were 75-pounders.
Really, though, what Jim is talking about here isn't what I found most impressive. I watched Jim do 17 one-armed pull-ups; that I found astonishing. I believe he quit doing these, however, because they were hard on his shoulder.