When I was too old to know better, I believed that there were swimming pools on top of RV's because of the ladder on the back - hey, it looked like a pool ladder!
A childhood belief about swimming pools

others believed things like this
- I believed that the ladder on the back of a trailer/rv led up to a swimming pool.— marilese
- I believed travel trailers had a pool on top because the curved ladder was the same.Anon
- I used to think that the expression "The former or the latter?" was actually "The farmer or the ladder?" — Fitzwilliam
- When i was litttle i used to believe that if a had a long enough ladder a could touch the sky.— Sarah Howell
- I used to think that the pools was a swimming competition.— Matt
- Up until I was in 3rd grade I believed my bathing cap is what kept me afloat in the swimming pool! Anon