I thought that the colour of your eyes determined how well you could see that particular colour.
E.g., if you have blue eye's you could interpret blue more deeply than someone with brown eyes.
I reasoned that the reason this wasn't common knowledge was because there was no objective way for one person to say how "blue" blue was to them.
A childhood belief about eyes

others believed things like this
- I was born brunette with brown eyes and dark hair, i thought people with blue eyes, had water in them.Anon
- Eifel 65 - Blue
I'm Blue (if I was green I would die...)
[I'm blue, da ba dee, da ba di.]— Matt - You know the eifel65 song "Im blue da be da ba di"
I thought he said "I'm blue I'm in need of a guy"— Anna - i used to believe that people with blue or green eyes saw that certain color— mellactica
- The song "Reverend Blue Jeans" turned out to be "Forever in Blue Jeans." Who would have believed that?— music lover
- I always thought the lyrics in I'm Blue were "I could beat up a guy"— Trisha Gaurav