This is quite similar to the belief about gunpoint being a physical place, but when I first heard about certain items being sold "on the black market" on the news one day, I believed that the black market was an actual place. I imagined it to be a famous and popular marketplace somewhere in the world, just like any other market in a big city. When I found out that it was used to sell many illegal items I asked my mother why the police didn't just go there and shut it down, since everyone knew which city it was in.
A childhood belief about places

others believed things like this
- I used to belive that the black market was a place— Lyndsey
- When I first heard the words "flea market", I actually thought it meant "selling fleas".Anon
- When i was a child, i thought a flea market was where you bought fleas.— Vanessa
- I used to believe that electricity was manufactured in a factory in a place called 'Electriz City'.— Sally
- I always believed that we lived in Manchester (we didn't) but it was always the main place on the local news!— Richard M
- I thought drug stores sold drugs. I never understood how they could sell illegal drugs.— Diana Rios