We live in a state that gets threated by hurricanes every year, so on major highways and such we had Evacuation Route signs. When I was little I used to believe that escaped criminals put up those signs to tell their prison friends where to go. Whenever I heard about a prisoner breaking out of jail I wondered why the police didn't just follow those signs.
A childhood belief about criminals

others believed things like this
- Having seen enough red octagonal STOP signs in my time, I used to look out for green circular GO signs.— Gary
- Up until I was 17 I thought that 'no outlet' signs meant that the steet didn't have any streetlights.— Kelsey
- As a kid, I thought "No Outlet" signs meant the houses past that point didn't have any electrical outlets.— Julie
- I always though as a kid that "To Let" signs were public conveniences with an I missing. Really.— Col
- When I was a kid, I used to believe that the "ped x-ing" signs meant "pediatrician crossing."— Jessica
- i used to believe that the signs for curvy roads were for snake crossingsAnon