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/
I’m still disappointed that 27 never managed to get on this list: https://www.youtube.com/watch?v=U2-7CqYFi64