I thought the word debut was actually "day view" since it was the first time the thing saw the light of day. Even when I did read the word for the first time I thought it was pronounced "debbut" till someone corrected me
A childhood belief about reading

others believed things like this
- When I was young, I heard the word 'minion' for the first time and thought it was a miniature onion.— Karin
- When I was young I used to think that WHSmith was all one word, and was thus pronounced "Wwwhhhhuuusmith"— Nathan
- I used to believe that the word 'circumstances' was pronounced 'circus dancers'.— Mel
- When i first saw the word "Czech" somewhere, i pronounced it "siz-ETCH" in my head — Pachisu
- In first grade, I thought that if I've never heard of a word before, then it wasn't a word.— Destiny
- I used to think that on day light savings time you had to stay up till 2:00am to change the clocks! — Sandy