As a child, whenever I saw under the hood of a car, the radiator fan seemed to be the only obvious thing that was turned by the engine. So I thought for some time that the fan was a propellor that propelled the car, much like an airplane propellor propels the plane.
A childhood belief about cars

others believed things like this
- My friend's sister used to think the auto pilot on a plane was an inflatable man like the one in Airplane!— Richard Davies
- i used to believe that every time i farted i was being jet propelled.— chuckipoo
- I used to think "Robin Hood and his merry men" was "Robin Hood and his *married* men."Anon
- I used to think that motorcycles were propelled by farts.— Meredith
- I used to believe that cars were propelled by their exhaust like some kind of rocket.Anon
- I used to believe that car exhaust pipes were what propelled cars, instead of the engines.— Thomas Johnston