For years I convinced myself that I had invented the word "stereotypical" and was really pleased at how much it had caught on. A little part of me still believes this. I haven't had proof it was around before 1975...
A childhood belief about speaking

others believed things like this
- Up until 8th grade or so, I was convinced that I invented the word "Fart"— Jonah
- I used to believe that I actually invented the word "excellent".— poop jacket
- I thought that some animals had just been "invented" recently (like within the last 50 years or so)— Makron
- i used to believe that bras were bullet-proof vests for women.— emily
- My 5 year old daughter believes if she picks her nose her bum will fall off !!Anon
- Apparently from seeing EKG's on TV, my daughter believes people die when their heart stops "beeping."— Jager