When I was in the second grade I heard something at school that showed me I didn't understand where babies came from. When I got home from school I asked my mother to explain it. She got all uptight and sat me down in the living room to explain it to me. Dad was at work. She told me that when two people who are married want to have a baby, the man inserts his penis into the woman and it creates a baby inside the woman. I didn't know about erections and didn't understand how what she said was possible. I asked her how difficult it was for the man to put his penis into the woman. She told me it was "a very simple operation". To me, an operation meant going to the hospital and having doctors do stuff to you. I asked her how long the man and woman had to stay in the hospital. She said they could do it without going to the hospital.
I left the discussion with the knowledge that when a man and woman wanted to have a baby they had to go to the doctor's office, where the man's penis could be stuck into the woman in a "very simple operation". That knowledge made me understand that sex was something to be dreaded, because no one wants to go to the doctor for an operation. That discussion messed me up for many years.
A childhood belief about sex

others believed things like this
- I used to think that if a black woman or man and a white woman or man had a baby, it would be Asian.Anon
- My sister just recently realized that the lyric "more than a woman" wasn't 4 letter woman!— Anne
- I thought the line in the song "more than a woman" was "four-legged woman".— boo
I used to believe a man and a woman needed a doctor to put their parts together when they did it.— Phil- I used to believe once a man and a woman lay naked caressing each other, the woman would be pregant— oiman
- I used to think that the song "Evil Woman" was "Medieval Woman". Anon