That's an exaggeration, of course.
One of the interesting things in writing the game is when you're contemplating a pop culture reference, quoting (or misquoting) someone or something, and so on.
You find yourself wondering what proportion of people will get it and whether people who don't are going to miss out on anything important, particularly if they aren't from the UK or the US. That's another reason for the little "info" dialogs that come up now and then.
After twenty-odd years in the US, there are still things I say that friends here don't get, and things I would love to share but that would require ten minutes of exposition.
My favourite joke ever requires that someone "gets" a British northern accent. Major frustration!