One man told of how his parents were alcholics and their house burned down (Kansas I think). He was shipped off to Boys Town and probably did fight. A priest tied him up and hauled him to Boys Town. I did learn that you can't take some of those stories at face value. It makes it harder to get at the truth.
I rather liked the happy nun in the "Sound of Music". That was Hollywood though.
The only nuns I ever knew are old now or deceased. They seemed pretty decent. My friend is an ex-nun and had to have knee replacements. She thinks it was caused by having to scrub hard floors on her knees in the convent. Her sister who was never a nun had to have a hip replacement, so it could have been genetic and had nothing to do with convent life. Another girl told of how she had been forced to scrub some statue or something for hours on her knees as punishment. Others told of being whacked on the hands with rulers. Allowing for exaggeration and outright fabrication, I think there was an element of truth in some of the stories I heard.
One catholic therapist told of having her nose broken by her mother (family member - not clergy related).
Before that, my perception had been that they were very strict but not necessarily cruel.