It's a reference to the book Hitchhiker's Guide to the Galaxy where:

a) the number 42 plays a significant role b) the towel is hailed as the most useful thing a galaxy hitchhiker could possibly posses.

So Don't Panic and don't forget your towel :)

Really curious to see how long the more popular subreddits will remain private. Surely the admin won't just turn them public again without having any mods, right? I kinda would love to see that dumpster fire.