I had a friend called Hermione decades before Harry Potter was invented, so I knew how to pronounce it.
My family was very pronunciation-conscious because we had a surname that wasn’t pronounced at all the way it was spelt. I’m not going to divulge it, but regret giving it up when I married. We might say ‘hyperbowl’ as a joke. My Australian MIL always talked about her ‘gaze-bow’, and that was also a joke.
I have a highly educated friend who talks about her ‘poinsi-etta’ every Christmas. I am longing to tell her to read the word more carefully.
As a young child I came across the word ‘decent’ in an Enid Blyton book. (It’s a very Enid Blyton sort of word, come to think of it.) I’d never heard the word, and pronounced it ‘descent’ to myself, but I don’t think I ever said it aloud.