There's probably a word I've been pronouncing wrong my whole life that I don't know about
Just based on how often I notice someone mispronounce a word without realizing it (or have done so myself and realized it later). Statistically I'm probably still doing it with some word.
There is probably lots of stuff like that in coding. Href could be “huref, and it took me a while to realize that it was ‘em’ and not just ‘m’ after hearing it.
Lol at my job someone referred to "E T C" and I was completely baffled until he actually typed it out, /etc... I just call it "ets" because it's short for "et cetera"...