My Mum used to think that boys willys continued to grow longer as they got older. She thought that it would hang down one of their legs and this is why little boys could wear shorts but men had to wear trousers. This also explained the bulge in swimming trunks because the man had rolled it up.
A childhood belief about rude bits

others believed things like this
- I used to believe that young boys belly buttons would soon change into there willys...Anon
- i used to believe you could get pregnant from swimming with boys.Anon
- I never knew why boys had to lift up the toilet seat...until my friend told me that boys had bad aim.Anon
- I used to believe the Beastie Boys were a boy band. Well, the name sounds similar to Backstreet Boys!Anon
- I thought that your period came out all at once and you had to wear a pad around the time it would come.— Sarah
- i used to think that had to wear diapers when you were on your period— Jess