Okay when I was younger I happened to catch an episode of Roseanne where the daughter was all pissy and mentioned getting her "period last night." I had no idea what that was, so one day at dinner, I ask out loud "Mom, what's a period?" Her boyfriend looked up and goes "The dot at the end of a sentence." Now, I knew that wasn't it, but I didn't press the matter.
A couple days later I was in the bathroom when mom started getting ready for a shower. She took her pants off and I saw a string hanging from her ladyarea, and I was like "Mom, what's that?" and she goes "That's my period." So for like, years after, I thought the period was when a string hung from your lady part. Haha
A childhood belief about periods

others believed things like this
- i used to thought that period is when you pee like a baby for a few days...— i'm totally weird
- I was horrified when my first period arrived. It wasn't blue, like in the commercials for sanitary towels.— Jane
- For years I thought that spunk was a male period and that boys spunked once a month - Yeah right!— Stupid Child
- My mom told my sister that if she didn't eat her peas, her period would last for an entire month.— Maya
- In 6th grade, I thought that once you got your period, you'd have it forever!!!! 24/7Anon
- I thought that your period came out all at once and you had to wear a pad around the time it would come.— Sarah