I've been quite lucky I think.
I once had booked a late check-out and the staff knocker and woke me up. I was so annoyed as I don't sleep well anyway and had been to a festival that didn't end until about 02:00 the previous night hence paying for the late check-out in the first place!
Another time went away with a new ish partner and the loo didn't flush. Rather embarrassing. It did after several attempts but not great.