When I was little, I had heard somewhere (can't remember where for the life of me) that boogers were house flies that landed in your nose, died, and had began decaying.
A childhood belief about picking my nose

others believed things like this
- I used to think bogies were made of dead flies which had flown up my nose.— Kate
- I used to think there were little booger factories in your nose that made boogers.— Melith
- My brother used to believe that dried out boogers were actually "paving" the inside of your nose. — sm
- One day i told my mom that i wouldnt pick my nose until the boogers made it look like i was a walrus— Lotta Thang
- Boogers came from magical booger fairies that mined them over night and put them in your nose in the morning.— Vivian
- I use to believe that dragon flies and fire flies were fairies— lady eberly