When I was younger, I used to believe that the road sign depicting the motorway in the UK was in fact a monster, with the bridge forming the arms, and the road beneath it making the head and legs. I was always relieved when we got of the motorway, because the sign had a line through it, so there were no more monsters.
A childhood belief about road signs

others believed things like this
- I used to believe that "the motorway" was one big long road that went absolutely anywhere in the world!!!Anon
- I used to believe the "Yield" from the road sign was somebody's name.— julia
- i always thought that a DEAD END sign
as where they put all the road kill.
— pav - I used to think that we were breaking a law every time my mom passed a "Do Not Pass" sign on the road. — Kyra
- i used to think that the road sign "dangerous" was actually "dang-er-roos" a kind of bouncy marsupial— owen cash
- I thought for the longest time that a No Standing traffic sign meant no person should stand near that sign.— Shannon