“Two random variables were talking in a bar…” (bar joke)

“A guy walks into a bar…” is a typical form of what has been called the “bar joke.” A math version is:
 
“Two random variables were talking in a bar. They thought they were being discrete, but I heard their chatter continuously.”
 
The joke was cited on reddit and was first cited on Reddit—Statistics and Twitter on May 7, 2013.
   
 
Reddit—Statistics
armchairdetective May 7, 2013
Not really a joke, but it makes me laugh hysterically:
Two random variables were talking in a bar. They thought they were being discrete but I heard their chatter continuously.
   
Twitter
Mads
‏@mitmads
Two random variables were talking in a bar. They thought they were being discrete but I heard their chatter continuously. (from reddit)
11:15 AM - 7 May 2013
 
Business Insider
13 Jokes That Every Math Geek Will Find Hilarious
Walter Hickey  
May 21, 2013, 5:38 AM
(...)
JOKE #2
Two random variables were talking in a bar. They thought they were being discrete but I heard their chatter continuously.
Source: armchairdetective /  reddit
 
Explanation: When you roll a die, you either get a 1, 2, 3, 4, 5, or 6. Since there are a finite number of possibilities, the statistic involved is called a discrete random variable. When you select any real number from between 0 and 1, there are an infinite number of possible draws. The statistic involved is called a continuous random variable.
 
Twitter
Chetan Mitta
‏@ChetanReddy
“Two random variables were talking in a bar. They thought they were being discrete but I heard their chatter continuously”- #Reddit #Nerd
8:48 AM - 21 May 2013
 
Calculus Humor
Random Variables
8/12/2013
(...)
Explanation: When you roll a die, you either get a 1, 2, 3, 4, 5, or 6. Since there are a finite number of possibilities, the statistic involved is called a discrete random variable. When you select any real number from between 0 and 1, there are an infinite number of possible draws.
 
Facebook
Calculus
November 2, 2015 ·
Two random variables were talking in a bar. They thought they were being discrete but I heard their chatter continuously.
 
Google Books
Comedy Writing Secrets:
The Best-Selling Guide to Writing Funny and Getting Paid for It (Third Edition)
By Mark Shatz and Mel Helitzer
Blue Ash, OH: Writer’s Digest Books
2016
Pg. 212:
Another safe target is academic subject matter. It’s highly doubtful that the following math jokes will trigger PC alarms.
 
Two random variables were talking in a bar. They thought they were being discrete, but I heard their chatter continuously.
 
Reddit—Jokes
Two random variables were talking in a bar
submitted August 21, 2016 by Kenzlea
They thought they were being discrete but I heard them continuously.
 
Twitter
Oxford Maths‏
@OxfordEdMaths
Two random variables were talking in a bar. They thought they were being discrete but I heard their chatter continuously #FridayJoke
11:30 AM - 21 Jul 2017
 
Reddit—Jokes
Two random variables were talking in a bar…
submitted July 30, 2017 by TheHickoryDickoryDoc
They thought they were being discrete, but I could hear their chatter continuously.