I used to think that kidneys were where babies ('kids') came from.
A childhood belief about general

others believed things like this
- I used to believe that kidneys were located in your knees.Anon
- I thought your loins were kidneys, and nobody corrected me until I was a teenagerAnon
- I used to think that people who donated their kidneys were doing it for steak and kidney pie.Anon
- I used to think the suction of an aeroplane toilet was large enough to suck your kidneys and spleen out.— Big Chrissy S_ _ _ _ _
- i used to belive that kidney beans were bean shaped things that grew in kidneys... untill yesterday — Jokey
- I used to believe that babies were born out our bellybuttons.Anon