When I was young, I was told that when eating fruits such as watermelons which has lots of seeds in it, if you accidentally swallow those seeds, a watermelon plant might just grow on top of your head. Same goes for other fruits like oranges or grapes. And I believed that until I was like 7 years old when common sense finally kicked in.
A childhood belief about seeds

others believed things like this
- If you eat watermelon seeds a watermelon will grow in your tummy and vines will come out your earsAnon
- when you eat the seeds from a watermelon a watermelon will start to grow inside your stomache.Anon
- I used to believe that if I ate a fruit's seeds, a plant would grow in my stomach.— Natalia Castillejo
- I used to think that if i ate watermelon seeds they would grow out of my ears.— Catherine
- If you eat your fruits and vegetables you will grow much faster and your muscles will be very happy!— Bruno
- In primary school, a whole bunch of kids including me believed that watermelon seeds contained ants. — Caff