In about third grade, my best friend "taught" me about the birds and the bees. I learned the typical procedure, up until the end when the man "pees" in the woman. Apparently, she knew something came out of his penis, just not what exactly. I thought this was true for the longest time until it finally dawned on me that pee is a waste product, and why would you purposely expel your waste into someone else?
A childhood belief about reproduction

others believed things like this
- I used to think water towers were where everyone's uh...waste...went to from the toilets.— Stephanie
- I used to believe that when you flushed an aeroplane toilet the waste would just drop out of the plane.Anon
- i thought that when you die they retire your email adress (apparently it's not true)— Nanofreak
My friend used to believe that bees made honey and jam.
— julia- when I was little, about 4th grade, I thought that when a guy had an erection his penis turned colors...lmao— peanut
- I used to think circumcision was a violent procedure performed on boys if they'd been "bad". — Tufty