“A guy walks into a bar…” is a typical form of what has been called the “bar joke.” A popular version has a man walk into a bar and shout, “Give me a beer before problems start!” He has a few beers, then the bartender asks how he is going to pay for it. “Now the problems start!” he replies.
 
The bar joke has been cited in print since at least 2003.
   
     
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Thread: Worst “x” guys walk into a bar jokes
ikf   
10-27-2003, 02:00 AM
(...)   
A man walks into a bar, sits down and orders a Bud. He says “Give me a beer before problems start!” The bartender doesn’t understand but gives the man a beer. After 15 minutes the man orders a beer again saying “Give me a beer before problems start!” The bartender looks a little bit confused but pours the man a beer. The goes on the whole night and after the 15th beer the bartender is totally confused and asks the man “What do you mean with before problems start, when are you going to pay for the beers you drunk.” The man answers “You see right now the problems start!”
   
Google Books
Guy Walks Into A Bar…:
501 Bar Jokes, Stories, Anecdotes, Quips, Quotes, Riddles and Wisecracks
By Michael Lewis
New York, NY: Black Dog & Leventhal Publishers, Inc.
2005
Pg. ?:
A man walks into a bar and says, Give me a beer before problems start! He drinks the beer, and says again, Give me a beer before problems start! The bartender looks confused. This goes on for a few more rounds, and after the fifth beer the bartender is totally confused. When are you going to pay for these beers? he asks. The man answers, Now the problems start!
 
Dizgraceland
Wednesday, December 14, 2005
Is this thing on?
(...)
A man walks into a bar and says, “Give me a beer before problems start!” Again, the man orders a beer again saying, “Give me a beer before problems start!” The bartender looks confused. This goes on for a while, and after the fifth beer the bartender is totally confused and asks the man “When are you going to pay for these beers?” The man answers, “Now the problems start!” 
 
Google Groups: novell.community.chat
media exaggeration
Sewermonger
3/15/06
(...)
A man walks into a bar and says, “Give me a beer before problems start!” Again, the man orders a beer again saying, “Give me a beer before problems start!” The bartender looks confused. This goes on for a while, and after the fifth beer the bartender is totally confused and asks the man “When are you going to pay for these beers?” The man answers, “Now the problems start!”.
 
Kotaku
WIN! Dawn Of War II And Limited Edition T-Shirt
David Wildgoose
Feb 19, 2009, 9:00am ⋅
(...)
COMMENTS
namarrgon @Namarrgon
Feb 19, 2009, 12:48pm
So, a Space Marine, an Ork and a Tyranid walk into a bar. The bartender, thankful that he paid his insurance last month, goes up to the Space Marine, who shouts, “Hurry man, give me a beer before the problems start!” The bartender turns pale, casts frightened glances at the Ork and Tyranid, quickly pushes a beer in front of him and leaves without even asking for money.
 
He then approaches the Ork, who snarls, “Oi! Gimme dat beer before dem problemz start!” The barkeep looks nervously at the Space Marine and Tyranid, and serves him straight away, gratis.
 
Lastly he goes to the Tyranid, who hisses, “Beeeeerrrrsssss! Before the problemsss!”. The bartender checks the other two, but they’re sipping their beers and sitting quietly, showing no signs of violence. So the bartender relaxes a little, and says, “Alright, but who’s going to pay for all these beers?”
 
The Tyranid rolls his glowing eyes and says, “Sso, now the problemss sstart.”
 
Facebook
Humour Touch
August 3, 2016 ·
A man walks into a bar and says, “Give me a beer before the problems start!”
 
He drinks the beer and then orders another saying, “Give me a beer before the problems start!”
 
The bartender looks confused. This goes on for a while, and after the fifth beer the bartender is totally confused and asks the man “When are you going to pay for these beers?”
 
The man answers, “Now the problems start!”
         
Reddit—Jokes
Posted by u/SplitzerShitzer March 30, 2017
A Guy walks into a bar
A man walks into a bar and says, “Give me a beer before the problems start!” He drinks the beer and then orders another saying, “Give me a beer before the problems start!” The bartender looks confused. This goes on for a while, and after the fifth beer the bartender is totally confused and asks the man “When are you going to pay for these beers?” The man answers, “Now the problems start!”
 
Reddit—Jokes
Posted by u/ayeroflmao May 18, 2017
Give me a beer before the problems start!
A man walks into a bar and says, “Give me a beer before the problems start!”
 
He drinks the beer and then orders another saying, “Give me a beer before the problems start!”

The bartender looks confused. This goes on for a while, and after the fifth beer the bartender is totally confused and asks the man “When are you going to pay for these beers?”
 
The man answers, “Now the problems start!”
 
Google Groups: Knights of Columbus - St. Timothy Council 12834
KofC TGIF 10-27 & Last Call to Action Request
doug.kofc12834
10/27/17
Greeting Brother Knights,
 
A man walks into a bar and says, “Give me a beer before the problems start!”
 
He drinks the beer quickly and then orders another saying, “Give me a beer before the problems start!” The bartender looks confused. This goes on for a while, and after the fifth beer the bartender is totally confused and asks the man “When are you going to pay for these beers?”
 
The man answers, “Now the problems start!”
   
Reddit—Cleanjokes
Posted by u/Agodthatbleeds April 30, 2019
A man walks into a bar and says, “Give me a beer before the problems start!”
He drinks the beer and then orders another saying, “Give me a beer before the problems start!”
The bartender looks confused. This goes on for a while, and after the fifth beer the bartender is totally confused and asks the man “When are you going to pay for these beers?”
The man answers, “Now the problems start!”
COMMENTS
nettnutt22
i thought for sure it had something to do with his wife walking in the bar