#14: Snow Joke
This one genuinely blows my mind. Even if you are the least well-educated American and have never left the country, how are you not aware of where it snows? Surely movies about Santa at the North Pole and those Coke commercials with the polar bears would have clued you in that some places are far snowier than the US.

However, in response to the poster’s second claim, I will say this: the thoroughly moronic charity single “Do They Know It’s Christmas?”, which contains the thoroughly moronic line “There won’t be snow in Africa this Christmas time,” was written by a Scot and an Irishman. Being unaware it snows in Africa is not a purely American trait.