this happened when i was in the 5th grade in school.i happnened to be at the club with a friend and saw the notice "today is a dry day".i actually asked my friend,"why is the swimming pool closed today?".i thought they must have 'dried' out the pool due to maintenence reasons.
A childhood belief about swimming pools

others believed things like this
- Up until I was in 3rd grade I believed my bathing cap is what kept me afloat in the swimming pool! Anon
- I used to think that a "pool shark" was an actual shark that lived in a swimming poolAnon
- I believed that the ladder on the back of a trailer/rv led up to a swimming pool.— marilese
- I used to believe that if you farted while swimming in the pool, it could propel you foward really fast.— Rick
- When I was a kid I used to think the "carpool lane" was an actual pool cars went swimming in— skeez
- I believed that the Kreepy Crawlie used to clean our pool, would follow me around the pool and eat me. — Mother-of-2