Title text:
In 1899, people were walking around shouting '23' at each other and laughing, and confused reporters were writing articles trying to figure out what it meant.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3184/
Maybe not a teen thing, but among children I think "because 789" could bring 789 into the discussion.
That only works in English though and while it does have a pun, I dont see it gaining any cult status...