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/
What the h311 is wrong with you? Us millennials invented 1337!
Nope. Source: am gen X.
Yep I think pops here has this one, us Millennials grew up with leet speak, it already was a thing in the 80s.
People get confused because leet speak had a resurgence around 1997 or so.