When I was barely able to communicate (probably about 3), my sister convinced me that if I ate one of my mom's houseplants I would turn into a koala. Nothing happened. Which I guess is good, since I didn't die or get poisoned. Not too many days or weeks (or maybe months since I didn't have much notion of time back then), she convinced me that if I ate wood I'd a beaver. We still have furniture with gnaw marks.
A childhood belief about i'm different

others believed things like this
- My sister told me that if you had sweetcorn in your poo, you had six months to live! I cried for weeks — Billy
- I used to believe that every country in the world had the same time. Guess I didn't consider time zones eh?— what are time zones again
- I thought that exclamation marks were actually "explanation marks", since they explain how you pronounce it.— superoid
- a friend was convinced that his school was an asylum, and couldn't be convinced otherwiseAnon
- My sister convinced me that rain was God's pee.— Scott
- My sister was convinced that when she grew up she was going to have puppies instead of babies— leohauoli