I used to think that being "sexually active" meant you had gone through puberty and were menstruating and able to have children. When I was 15 I read an article in Cosmogirl that said if you were sexually active you should start seeing a gyno, so I told my mom, "I should see a gyno now since I'm sexually active." That was a fun and briefly awkward conversation while she figured out what I meant.
A childhood belief about virginity

others believed things like this
- I used to believe that chickens reproduced A sexually and that roosters were just handicapped chickens. — Teena Strang
- i use to think that clouds were made from active volcanoes— brandyn
- i used to believe that sex meant love and that having sex meant the two people would live happily ever after.— amy
- I used to believe that a street sign that read "Dead End" meant that there were dead people buried there.Anon
- I used to believe that when I started menstruating, I would bleed to death from losing too much blood.— Debbie
- Someone told me People and fish went to the same place.I thought they meant humans get flushed— MrK