When I was a kid I had a bunch of pet Gerbils. My brother somehow convinced me that gerbils were horses that were bred down to size.
A childhood belief about general

others believed things like this
- My brother believed that bacon(his favorite food) was from horses. — Jenn
- When I was little I thought cows married horses, cows were all female and horses were all male. — Sheila
- My brother once convinced me that the wind was "leftover hurricanes"— Tufty the Squirrel
- I watched a Michael Jackson music video with my brother, and we were convinced he was a woman.— Adrian
- I used to believe that horseradish
was made from horses.— Dee - I used to believe cows were ugly horses— Marlene