My Dad used to tell me that the snot coming out of my nose was brain matter oozing out - that my nose would eventually quit running because I'd be out of brains!
My Mom let him deal with it when she found me sobbing uncontrollably later in the day ...
A childhood belief about general

others believed things like this
- I used to believe if you picked your nose, your brains would fall out your nose.Anon
- my mum once told me if you picked your nose your brains came out!!!!— smiley : )
- if you pick your nose your brains will fall out!Anon
- My wife used to tell our kids that if you pick your nose your brains would fall out— grampy
- i used to believe that if you picked
your nose your brain would cave in...— mr bogtrotter - when i was little my mum used to tell me if i picked my nose too much my brain would fall out!!! think it did— Maz