I used to think that my parents only "did it" to have children and then they didn't do it anymore. It wasn't until I was a teen that I realized that wasn't true.
A childhood belief about sex

others believed things like this
- i used to think only children whose parents don't want them anymore goes to childcare centre.— Long long ago
- I used to think that if you ate cat food you would die. I found out it wasn't true
— Bob#4 - I used to think that my right hand wasn't my right hand anymore if I turned around.— Mike
- My sister just recently realized that the lyric "more than a woman" wasn't 4 letter woman!— Anne
- I used to believe that aliens would come and take me if I wasn't good to my parents— somebody
- I used to believe that vanilla wasn't a flavor. It just didn't have chocolate in it!— Andrea