One hot summer's day my dad asked me if I'd make him a water, but to make sure the water was cold he told me to 'let the tap run'. Seeing as the tap was a stationary fitting I of course found this very confusing...
A childhood belief about bathrooms

others believed things like this
- I didn't think you could put out a fire with hot water - only cold water would do.— Katti Pytt
- I used to believe that hot water was red and cold water was blue.Anon
- When I was little, I thought you had to put a finger under the water to make it hot. — M_2
- I used to believe all liquids were water-based with things added to it to make different kinds of liquids.Anon
- I asked my father what holy water was. He told me it was the priest's bathwater. — Gwen
- I thought that hydrogen was pure water (since I knew hydro- meant water) and H2O was impure some how— Hexetic