My mate Fawce used to go to his Grans for tea, but the milk always tasted funny to him (it was that stuff from a tin). His Dad told him it was Bull's milk and he believed it and always asked his Gran for Bull's milk in his tea, until he was about 18 and he told the story in the pub - he then realised that bull's milk could be also called sperm.
A childhood belief about milk

others believed things like this
- that black women breastfed chocolate milk instead of white milkAnon
- I used to beleive that milk bottles were filled with milk, directly from the cow's udder.Anon
- When we were little my sister thought if you mixed cow’s milk and water you’d get goat’s milkAnon
- I used to believe I could milk dogs like the cows. This was because I saw a nurse milk his cow.— Laurent and Alexis, French students in eighth grade
- I didn't believe that a cow's milk and the milk in the fridge were at all related!Anon
- I used to believe chocolate milk came from brown cows and regular milk came from black and white cowsAnon