I never really realized how weird this is to an international audience, because it’s so incredibly ingrained in society in the Nordics, because the school year cutoff is the calendar year, so kids are always grouped together by birthyear.



This means that everyone mentally groups together people of the same birthyear as being the exact same age. And people born the next year are all one year younger.



For example, in S2E1, Eva is making fun of Jonas because he’s flirting with a ‘00 girl. Eva’s birthday is in June, Jonas’ birthday is in December, so there’s an almost 50% chance that this anonymous girl was born in early 2000, which would make her closer in age to Jonas, than Eva to Jonas.



But none of that matters, their actual age doesn’t matter. Jonas and Eva are ‘99ers, this girl is a ‘00, so Jonas and Eva are the same age, and this girl is one whole year younger.