A childhood belief about condoms

I was given the birds and bees talk at a nice young age, as I believe my parents were absolutely terrified (and rightly so!) about what I might hear later at school if they didn't head off the nonsense, as it were.

I was in a conservative family and had no concept whatsoever of sex for pleasure - I believed that people had extramarital sex because they wanted children but not each other, even by the time I was old enough that I should have known better . . .

For the life of me I couldn't figure out how a condom let sperm through but didn't let the AIDS virus through even though the AIDS virus is smaller. Confused me for two long years between ten and twelve - but no one wanted to talk about condoms, therefore it was very difficult to learn how they'd engineered this feat.

Oh, the strangeness of the world when I knew the relative size of sperm and viruses but not that people have sex for fun!!! Makes me laugh like mad now . . .