When I saw signs saying "Public Footpath", "Public Swimming Pool" I thought that "Public" was the name of a private club that you had to join to use these facilities. I remember asking my parents if we were members.
A childhood belief about swimming pools

others believed things like this
- When I was a kid, I wondered why they called it "public hair" when it was so private.Anon
- I thought the "To Let" signs on buildings meant they were public toilets.— Scottish Laddie
- I always though as a kid that "To Let" signs were public conveniences with an I missing. Really.— Col
- i used to believe that public houses were just houses were the public could go and liveAnon
- I thought Busch Gardens was a public garden owned by George W. Bush.Anon
- my mum told me that the 'public' park was closing so she could go home— xx-lotty-pop-xx