Are step-ladders like step-fathers? “I have a step ladder. I never knew my real ladder” is a popular joke of uncertain origin.
 
“It’s not my REAL ladder. It’s my stepladder” was posted on the newsgroup soc.culture.thai on January 6, 2015. “This is my step-ladder, my real ladder left me when I was a kid” was printed in The Sun (London, UK) on December 28, 1996.
 
“I spent the afternoon in the garden with my stepladder. Not my real ladder. My real ladder and I - we don’t get on well with each other any more…-Harry Hill” was posted on the the newsgroup uk.media.tv.friends on March 12, 2000. English comedian Harry Hill is frequently credited with the joke, but no known earlier citations have been credited to Hill.
   
   
Google Groups: soc.culture.thai
U.S. GREEN CARDS
Alan Dawson
1/6/95
(...)
* It’s not my REAL ladder. It’s my stepladder.
 
28 December 1996, The Sun (London, UK), “There’s no business like Joe business” by Garry Bushell, pg. 24:
Who else could get away with mixing childish gags like, “This is my step-ladder, my real ladder left me when I was a kid,’, with such knowing asides as, “What’s got 18 inches and speaks French? Moi! “
       
Google Groups: alt.silly.little.newsgroup
This is my stepladder
Jonathan
4/1/99
My real ladder left when I was 3.
 
Google Groups: uk.media.tv.friends
Quotefile
Corkster
3/12/00
(...)
I spent the afternoon in the garden with my stepladder. Not my real ladder. My real ladder and I - we don’t get on well with each other any more…
-Harry Hill
 
Google Groups: rec.humor.jewish
Puns of the Weak 01/11/02
Stan Kegel
1/12/02
(...)
I have a stepladder. It’s a very nice stepladder, but it’s sad that I never knew my real ladder. (Craig Charles)
 
Google Books
The Mammoth Book of Comic Quotes
London, UK: Constable & Robinson Ltd
2004
By Geoff Tibballs
Pg. ?:
I was doing some decorating, so I got out my stepladder. I don’t get on with my real ladder.
HARRY HILL
 
Twitter
Kosso 🌀‏
@kosso
“I’ve got a step ladder…... I never knew my real ladder” [Harry Hill]  heheheh!
1:27 PM - 13 Apr 2007
   
Twitter
jrb‏
@blandford
“This is my step-ladder.  It’s not my real ladder.”
9:48 PM - 19 Jul 2008
 
Google Books
The Mammoth Book of Great British Humour
By Michael Powell
London, UK: Constable & Robinson Ltd
2010
Pg. ?:
I have a really nice stepladder, but sadly, I never knew my real ladder.
Harry Hill
 
Google Books
The 2,548 Wittiest Things Anybody Ever Said
Selected and compiled by Robert Byrne
New York, NY: Touchstone
2012
Pg. ?:
2,104
I always use my stepladder because I don’t get along with my real ladder.
—Harry Hill
 
Google Books
Oxford Dictionary of Humorous Quotations
Edited by Gyles Brandreth
New York, NY: Oxford University Press
2013
Pg. 116:
I was decorating, so I got out my step-ladder. I don’t get on with my real ladder.
Harry Hill 1964– English comedian: attributed
     
Reddit—Jokes
I have a step ladder
submitted November 16, 2014 by Papajon87
I never met my real ladder .
 
Reddit—Funny
This is my step ladder. I never knew my real ladder. (imgur.com)
submitted June 5, 2015 by s_mclovin27
 
Reddit—Dad Jokes
I just got a new stepladder (self.dadjokes)
submitted June 14, 2015 by AkimboSavior71
I never knew my real ladder
 
Reddit—Dad Jokes
I recently got a step ladder (self.dadjokes)
submitted August 16, 2017 by SoDakZak
It hurts not being able to see my real ladder anymore.
 
Reddit—Jokes
I have a step ladder…
submitted August 24, 2017 by MattieWasTaken
I never knew my real ladder… :*(