A train joke was posted on Twitter by sickipediabot on September 19, 2012, and probably originated on the Sickipedia website:
   
“You’re the worst fucking train driver ever,” said my boss. “How many trains have you derailed to date?”
 
“It’s hard to keep track,” I said.
   
       
Twitter 
Mark Smith
@MjsUrko
“You’re the worst fucking train driver ever” said my boss.  “How many trains have you derailed to date?”  “It’s hard to keep track” I said.
5:51 PM - 19 Sep 2012
   
Twitter
Wayne Cunningham
@wayneo_cunny
“You’re the worst train driver ever” said my boss.“How many trains have you derailed to date?”“It’s hard to keep track” I said. #thankyou
5:55 PM - 19 Sep 2012
 
Twitter
sickipediabot
@sickipediabot
“You’re the worst fucking train driver ever” said my boss.
“How many trains have you derailed to date?”
“It’s hard to keep track” I said.
6:50 PM - 19 Sep 2012
 
Reddit—Dad Jokes
My boss said “You’re the worst fucking train driver ever,” (self.dadjokes)
submitted July 19, 2015 by Linalg2
“How many trains have you derailed to date?” I replied “It’s hard to keep track.”
 
Facebook
Dad Jokes
July 21, 2016 ·
My boss said to me, “you’re the worst train driver ever. How many have you derailed this year?”
I said, “I’m not sure; it’s hard to keep track.”
 
Reddit—Jokes
My boss said to me, “you’re the worst train driver ever. How many have you derailed this year?”
submitted November 6, 2016 by seksignome
I said, “I’m not sure; it’s hard to keep track.”
     
indy100 from Independent (London, UK)
6 jokes only people with a dark sense of humour will find funny
Posted 30 November 2016 by Narjas Zatat in offbeat
(...)
6.
My boss said to me, “you’re the worst train driver ever. How many have you derailed this year?”
I said, “I’m not sure; it’s hard to keep track.”
- seksignome
 
Reddit—Jokes
My boss told me, “You are the worst train driver ever. How many have you derailed this year?”
submitted February 10, 2017 by jasonhuang717
I replied, “I don’t know; it’s hard to keep track”.
 
Reddit—Jokes
My boss told me, “You are the worst train driver ever. How many have you derailed this year?”
submitted April 5, 2018 by mekokil75
I replied, “I don’t know; it’s hard to keep track”.
 
Reddit—Dad Jokes
My boss said to me, “you’re the worst train driver ever. How many have you derailed this year?” (self.dadjokes)
submitted August 23, 2018 by Natty383
I said, “I’m not sure; it’s hard to keep track.”
 
Twitter
Shit Jokes
@ShitJokes
My boss said to me, “you’re the worst train driver ever. How many have you derailed this year?”
I said, “I’m not sure; it’s hard to keep track.”
6:52 AM - 24 Aug 2018