I remember when my mum told me the facts of life I asked "so you and Dad have just done that once?"
I was utterly horrified when she explained people do it for fun and not just to make babies, couldn't look either her or my Dad in the eye for days!
Talking about looking my Dad in the eye. I don't know if any of you are familiar with the phrase "before you were a twinkle in your Dads eye". Well when I was very young I went through a phrase of thinking I got in my Mums belly because my Dad looked at my Mum and the twinkle in his eye passed to her eye and travelled to her belly haha. I spent ages refusing to make eye contact with my Dad!
I learned about the sperm and the egg at some point in childhood from a book for children about where babies come from, but I was not told what the means of conveyance was. I imagined that it had something to do with marriage: the wedding ceremony or something following it, I surmised, must cause the sperm to pass from the man to the woman (through the air). Then I saw an episode of a television series in which there was a scandal about a woman who was pregnant but had no husband. (This was in the 1960s, and the show was set in the 19th century anyway.) That overthrew my theory and caused me great perplexity. Then, when I was ten years old, I looked into a book that had been left lying around (presumably on purpose by my mother) called
Everything You've Always Wanted to Know About Sex, But Were Afraid to Ask, which was a best-seller at that time. I was astonished to learn that the playground lore about penises going into vaginas, which I had assumed to be a kind of joke, actually had a basis in fact.