I used to believe that every day of the week had its own colour.
Monday was yellow,
Tuesday was lilac,
Wednesday was dark green,
Thursday pink,
Friday orange,
Saturday red,
and finally Sunday was blue.
I never knew why, until I got older and realised those were colours used in our TV guide for every day of the week.
Still, to this day whenever I have to make an appointment, I think in "colours".
A childhood belief about general

others believed things like this
- I once refused to believe in Thursday. I'd heard there were seven days in a week, but could only name six.Anon
- i used to believe everyone saw different colours but just described the same.Anon
- I used to believe that if you mixed red, blue, green, and yellow paint you'd get plaid!— Judith Ann
- I thought that the Chewit wrappers were different flavours as they were different colours like the sweets— Helen
- I used to want to be a garbage man when I was older because I belived they only worked one day a week— Oscar the Grouch
- I used to believe that people's brains differed in colours. I always wanted purple brains for some reason.— Katrina