When I was young I believed that the drain in the back of the sink was to give the sink a drink. Every time that I brushed my teeth, I had to pour some water in the drain so that the sink wouldn't be thirsty.
A childhood belief about bathrooms

others believed things like this
- If you eat 30 minutes before swimming, you will sink.Anon
- i used to believe that a monster lived in the garbage disposal. i would never go near the sink— Whitney
- how many us believed you would go down the drain with the bath water? I did!— Amy
- I used to think that trolls lived in my shower drain and showered with my dirty water— Troll bather
- My mother told me that the tooth fairy would only come if I brushed my teeth.— Dale
- Until I was about 8 I believed that your back teeth keep growing in until you have a full circle of teeth.Anon