When I was young growing up in the country where we with dirt roads, I thought the main highway sign "Don't Drive on Shoulder" meant the girl sitting next to the guy couldn't put her head on his shoulder while he was driving. I thought this for the longest time, probably until I learned the rules to drive.
A childhood belief about road signs

others believed things like this
- I thought for the longest time that a No Standing traffic sign meant no person should stand near that sign.— Shannon
- I thought the no overtaking sign meant that red cars cannot drive by black cars.— Helen
- I used to believe that the lines on roads were for motorcycles to drive on.— Downes
- I used to believe that the "no outlet" sign on roads was a warning to people driving electric cars.— c
- At the age of about 5, I thought that any man carrying a bag/sack over his shoulder was a burglar.— Police officer, Ola.
- I used to think that the shoulder blades were actually "back breasts".— Kdees