My older brother told me that when you diled '0' for operator on the telephone, that a doctor performing an operation on someon (an 'operator') would have to leave the operating room to answer your call, and his patient could die from being unattended while the doctor was talking to you. He explained that is why you should never dial '0' on the phone - you could kill someone. He would then pick up the phone, dial '0', and make me scream.
A childhood belief about telephones

others believed things like this
- I always thought that my relatives were really tiny, and inside my phone when I talked to them on the phone.Anon
- I used to think that in the song "Smooth Operator" they were saying "Schooooooool's not forever!"— Steph
- When I was a kid I was completely convinced that Sade's "Smooth operator" was "Ooh of the red eye".— Brookstar78
- my uncle was a doctor, so when he told me his vw could fly, i believed.— boodles
- I used to think eating raw potatoes would give you "BEZORES".
Our family doctor told me this— Moodycop - I used to believe that one day, my younger brother would be older than me and then he'd pick on me!— Andrew