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/
No
https://en.wikipedia.org/wiki/The_Illuminatus!_Trilogy
Thank you. I didn't know what 23 was about