When I was a little (3 years old), I have drunk once same spoilt milk. And, because next time I refused to drink no more milk, my Gramma told me that it wasn't cow-milk, but it was guinea hen-milk. And I have drunk!
I had That belief for many years. Every time when the milk was good, I thought it was guinea hen-milk, and when it was bad, I thought that was cow-milk.
A childhood belief about milk

others believed things like this
- When we were little my sister thought if you mixed cow’s milk and water you’d get goat’s milkAnon
- 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
- 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