As a kid, my little cousin had poison ivy, and I was told that I'd get it too if he touched me. Needless to say he chased me around his house all day, and I was shocked when he caught me, tagged me, and I didn't immediately start itching or break out in hives.
A childhood belief about plants

others believed things like this
- I used to believe that if you touched Chinese people, they would break.— Christian
- I used to believe that the white boxes that housed bee hives were cow graves.— Bub
- I used to believe Serial killers would break into your house and stab/'kill' your cereal.— mary
- My uncle told me that if I didn't wash my ears when I took a bath, corn would start going out of them.— Ebod
- My cousin's mom told my cousin that pop makes you short. He probably believed it.— Molly
- I was shocked when I found out that dogs in foreign countries didn't know English commands.Anon