I used to believe that the reason toothpaste was effective was because of how it burned in my mouth. So it effectively burned the plaque and germs away. Same with Listerine.
A childhood belief about bathrooms

others believed things like this
- I used to believe that when a person was "fired" from their job, that they were literally burned at the stake.Anon
- I thought firefighters were really "firefires," and burned houses down insted of putting them out.Anon
- Burned fish fingers ment the fish was from the black sea.Anon
- For some reason I used to believe humans were made out of toothpaste— lu
- if you eat toothpaste straight from the tube, you will get worms— wormelow
- That germs came from Germany.— Alicia