you kinda answered your own question there didn't you?
I've probably jumped off of around 70 or so, backed down from bigger ones because I just wasn't feeling it.
Years ago we were hanging out at my friends cabin and after an afternoon game of Risk we headed over to the inner bay and had a good old fashioned cliff jumping session. There's a 20, 40, and 60ft (approx heights), three of us were jumping, the others were hanging out on the dock and in a canoe watching us. Hit the 20 a few times doing some flippy spinny tricks, went to the 40 and did some backies, eventually working our way up to the 60.
So, buddy jumps first, I hear him hit the water and come up, yelling "clear" when he was a safe distance away. I ran and jumped in, did the same thing, the lady in our jumping group was the last to go, and sure enough, after I gave the all clear we see her jump off the top and land feet first, pretty much upright - but when she surfaces her head is down and she's unconscious. Me being the closest I swim over and pull her head out of the water trying to keep her spine as straight as possible till my friend in the canoe who has proper first aid training came to take over. We get her up on the dock and she starts convulsing and spitting up a bit of blood, but still for the most part, unconscious. She ended up getting air lifted to Vancouver leaving us to think about life and stuff. In the end she got brain swelling around the back of the head and a broken collar bone, no real permanent damage. What we figure happened, is that even though she worked her way to the big cliff, when she jumped off and realized how big it was, she got scared and passed out in mid air - it would explain the nature of the injuries more so than any other scenario.
I guess the moral of my story is that shit can happen really fast when you start getting to bigger drops, so just never let your guard down and have a plan for if/when shit hits the fan, because you never know.