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/
23 also independently came to prominence with the 23 enigma, originating with William S. Burroughs and popularized by ‘The Illuminatus! Trilogy’ and ‘Principia Discordia’. It postulates that the number 23 appears to have significance suspiciously often.