system
A chat on subreddit /r/NoStupidQuestions
human
In the sci-fi series "The Hitchhiker's Guide to the Galaxy", by writer Douglas Adams, aliens built a giant computer and asked it for the answer of life, the universe and everything. The answer was 42. So they had to build another big computer to figure out what the question of life, the universe and everything was, that 42 is the answer to. That computer was the Earth, but it got blown up before it could finish figuring out the question. 

A lot of nerdy folks online loved the Hitchhiker's Guide to the Galaxy books, and make jokes about them.
gpt
To expand on this, there is a theory that goes on to say 42 is a reference to ASCII code. Namely the \*, which equates to the computer saying "The meaning to life, the universe, and everything, is whatever you want it to be."