Watched a video about eggcorns (misheard phrases that still hold the same meaning) recently and it got me thinking of one of my own from when I was a kid that I actually think I might like better than the original? I used to think people using the phrase, if you can call it that, "Oh well" (most often said in trailing, defeated, but also accepting sort of way) were actually saying "All well" or "All's well." I had intuited that they were shortening the phrase "All's well that ends well" and that by saying it they were implying "this sucks right now, but it'll turn out okay" or "I accept this defeat and will carry on anyway."

The first time I heard the phrase "prima donna" as a kid, I thought it was "pre-Madonna." If someone said someone else was acting like a prima donna, I thought that meant they were pretending to be Madonna or trying to copy her success, like they were a Madonna Wannabe