When I bought my current horse he had been sitting in a pasture for fifteen years after leaving a very abusive home and the only contact with people the horses got was when people threw the herd hay. I was told they rode him regularly and he was an amazing barrel horse. But in reality he'd gone completely feral and terrified of people to the point where he was going to be put down, which I found out after I'd bought him. But I was young and convinced I was invincible and could do anything. I lost count how many bones he broke and how many people told me he'd be better off with a bullet in his head but I wouldn't give up. He's amazing now but looking back I see how stupid it was and I would never do it again.
A woman brought a horse to the barn that she'd recently rescued claiming he was just young and unbroke. Turns out he had major territory issues and had been kicked out of three different barns because of it. If he thought you were invading his space he got pretty violent. She didn't think to tell me that before she asked me to train him so he showed up at my barn, a new place he hadn't claimed, and was an angel. Once on his back he reverted into a crazy screaming pogo stick. He cow hopped, dropped his corners, reared, bucked, and did everything he could to get me off. Once he jumped into a rear so hard he lost him balance, fell back through a fence, landed on me, and shattered my pelvis. He never did anything wrong again though because when I was cleared to ride again I didn't let him get away with anything. He didn't get to do anything until I let him. I ran into his owner a few years later and found out that he had to be put down because she let him get away with too much and he broke her arm lashing out at her.
Show me a horseman who hasn't fallen and I'll show you a man who has never truly ridden.