I used to believe that when a meal or drink was 'on the house' it was actually on the roof of the building.
("Why would someone put it ON THE HOUSE?")
A childhood belief about drinks

others believed things like this
- I used to believe that when you moved house you swapped house with the person moving into your old house.Anon
- when i was young i believed that when u moved house the house would come with you !!!
just like a turtleAnon - The Whit house down the street was the real "White House". — SG
- I used to believe that if you opened up an umbrella inside your house that the whole house would fly awayAnon
- I used to think the Empire State Building was called the "Ten-past-eight building".— Alex
- when i was younger i thought that when you moved house your house moved with you!!— chrissy