After my mom's finger was injured, she had to wear these finger bandages that looked like they were made of rubber that you just slip on. (I'm not sure what they were called.) I saw them, and I thought it was something entirely different. When I saw my mom slip it on her finger, I said aloud: "Is that a condom?" With a shocked expression. She got a good laugh out of that.
A childhood belief about condoms

others believed things like this
- I used to believe that a half moon was gods finger nail, and his finger was pointing downwards.— clo
- I used to believe that my grandpa had a special power that made him fart each time I pulled his finger. — confused
- When I was little, I thought you had to put a finger under the water to make it hot. — M_2
- When I was a kid I thought if I bit my finger off and swallowed it it would pop back into place— Mike
- Never point at a grave, if you do your finger will rot off.— KL.R
- I used to believe that if my finger was ever cut off, it would grow back.— Chrissy