“A guy walks into a bar…” is a typical form of what has been called the “bar joke.” A Pokémon Go version is:
 
“A Pokémon Go user walks into a bar. Because he was too busy looking at his phone to notice it.”
 
The bar joke was posted on Reddit—Jokes on July 8, 2016.
   
     
Wikipedia: Pokémon Go
Pokémon Go is an augmented reality (AR) game developed by Niantic for iOS and Android devices, initially released in select countries in July 2016. The game is the result of a collaboration between Niantic and Nintendo by way of The Pokémon Company. It uses the mobile device GPS to locate, capture, battle, and train virtual creatures, called Pokémon, which appear as if they are in the player’s real-world location. The game is free to play; it uses a freemium business model and supports in-app purchases for additional in-game items. It is the first mobile game in the Pokémon media franchise and video game series.
 
Reddit—Jokes
A Pokemon go user walks into a bar
submitted July 8, 2016 by texastoasty
Because he was too busy looking at his phone to notice it
     
Twitter 
me
@not_actuallyme
A Pokemon go user walks into a bar via /r/Jokes http://ift.tt/29zUbVo
11:19 AM - 8 Jul 2016
   
Twitter
Stephanie Melville
@WellyHandy
Replying to @katie_pai @MailOnline @ACCNZ
“A Pokemon Go user walks into a bar…............and a table, a wall, a cyclist, a lamp post, a tree 😜 “
4:10 AM - 10 Jul 2016
 
Reddit—Jokes
A Pokémon Go player walks into a bar…
submitted December 30, 2016 by [deleted]
Then into a tree… Then into a car…
 
Reddit—Jokes
A Pokemon Go player walks into a bar.
submitted April 6, 2018 by 1081_
And a tree. And a wall. And into a lake.
 
Reddit—Dad Jokes
A pokemon go user walks into a bar (self.dadjokes)
submitted August 5, 2018 by Gingo-ninjo
Then a sign, then a person