I remember in sex ed, in around the 4th grade, being told you got your period once a month. I took this to mean it was like a sneeze or something as it you had it...and bam you were done and went on about your business.
I'm sure you ladies can imagine my disappointment years later when I got it and discovered that "once a month" meant you got it and KEPT it for several days.
A childhood belief about periods

others believed things like this
- 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
- I was told in first grade that if you fart burp and sneeze at the same time you would blow up— bob doodle
- When I was little my sister told me salt was ground up dinosaur bones...I barley ate for a month...— Chandler
- My sister believed that october was the 10th month!— Sally
- The moon was actually either a sugar cookie or a banana, depending on the time of the month. — Jessica Aspra