I used to believe that organism and orgasm were variations of the same word. Then while reading aloud one day in Grade 7 science class, I replaced the word organism with the word orgasm. Most of the class, including the teacher began laughing. I was dumbfounded until about 1 year later.
A childhood belief about spelling

others believed things like this
- 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 the word fever was just another word for giraff— Marshall m
- Up until 8th grade or so, I was convinced that I invented the word "Fart"— Jonah
- I used to believe that the Chinese boy in my kindergarten class flew from China every day to get to class.— Debi
- I used to think my elementary school gym teacher's name was "Jim Class".— Brandon Campbell
- I used to believe that I actually invented the word "excellent".— poop jacket