One of them noted the the "/me" emote was from World of Warcraft. Of course, being an old, pedantic fart, I had to add my 2 cents by explaining how they were mistaken.
The /me emote actually pre-dates modern MMO's by a few decades. Back in the days of 300 and 1200 baud modems (yeah, one could actually type faster than they could display text), people with access to university computer systems (or a spare IBM XT) would set up what were called "MUDs" or Multi-User Dungeons. They were text-based like the old Zork games, but you could "see" and interact with other users through text chat and emotes.
So, the screen might read:
> You walk to the entrance of the Hedge Maze. Passageways in the hedge head off the the North and West. Steve_the_Barbarian and Sorcerer_Tonya are here.
$ /me wave
> Marty waves.
$ /say "Hey, what's up? Are you heading into the hedge dungeon?"
> Marty says "Hey, what's up? Are you heading into the hedge dungeon?"
> Sorcerer_Tonya waves.
> Sorcerer_Tonya says, "yup we're heading in"
> Sorcerer_Tonya invites you into the group.
$ /follow Sorcerer_Tonya
It was a lot of typing just to do pretty rudimentary stuff (and it was real time combat, so you had to type fast or have macros ready!)... but these were literally the first seeds of the modern MMO.
I'm not sure what the whole point of this post was except to think... Jeebus, we've come a long way and damn... I am old.