I learned when I was about 5-7. My parents had this book from God-knows-where that explained every facet of human biology in amusing cartoonish detail. In the sex and reproduction part, it had cartoony pictures of a naked boy and a naked girl, with their sex organs visible through their skin. Then on the next page it had a train-car with a cross-section of a penis attatched(all cartoon) going into a train-car with a vagina-like thing... Plus my mother was a natal-care nurse, so I got some stuff from her, too.
I wonder what happened to that book...
I wonder what happened to that book...