I was told when i was little that when you lie a blue spot appereared on your forehead until you admitted you'd lied.
A childhood belief about appearance

others believed things like this
- When I was young I thought that a parking spot was a spot like a polka dot and not a space for a car.— Mina Tova
- my mum used to say if i lied my eyes would change colour...when i lied i would shut my eyes— kevin rosenqvist
- Eifel 65 - Blue
I'm Blue (if I was green I would die...)
[I'm blue, da ba dee, da ba di.]— Matt - I used 2 beleive yer @$$ was yer foreheadAnon
- I used to believe that the wrinkles on my dad's forehead were his feelings.— Suzy
- I used to think my forehead was actually called a three-head.— Fen