When watching American TV and films, as a younger person, I’d consistently be amazed at how often characters would refer to a college class such as Biology 101 or History 101. Such lazy writing, I’d think. Why do they always say the classes are in Room 101? Why doesn’t even one writer decide to buck the trend and set their class in some other room? Even just Room 102!

I stopped thinking about it for a long time, after just getting used to it, I suppose. But at some point it occurred to me that of course those classes weren’t supposed to be in Room 101, but that 101 was a code to indicate it was a basic or introductory course.

I could be forgiven, I think, for my confusion though. First of all, we don’t use those numerical codes in Ireland. And, popular culture is full of shorthands and odd repetitions like the one I’d imagined. Such as the fact that every phone number in the United States seems to begin with 555. That one at least I managed to figure out: it was to avoid using real numbers accidentally in films or TV programmes.

Like 101, this only applies to the United States (other countries have their own fictitious numbers reserved for works of ficiton). And this reminds me of how separated we can be by different forms of the same language. Even though I understand what someone means whenever they use the This is _______ 101 expression, I’d never use it myself, because it’s so American.

They are never really any serious communication issues with such expressions for non-Americans. But when someone takes about Psych 101, or going the whole nine yards, it always makes me realise just how big this world is, and how expressions in your native language can spring from cultural contexts that are pretty alien to you.