I once thought the story of Alexander the Great cutting the gordian knot was made up for the Phineas and Ferb episode "Knot my Problem"
A childhood belief about cartoons

others believed things like this
- I used to believe your belly button was a knot that held you together - my parents had wierd anatomical views— anne
- I used to believe that Alexander Graham Bell was not just one person. I thought that they were three people!— J.D.
- When my cousin was younger his name was Alexander and he thought his middle name was "ander"Anon
- When I was about 3-5 I thought I could shave like my dad and I ended up cutting myself all over. — Matt
- I used to think that The Great Wall of China was made out of porcelain.— Morten Vestergaard
- When i was a kid, i thought that nematodes would eat our house like in one episode of SpongeBobAnon