“Don’t mess with success”

“Don’t mess with success” is another way of saying “if it ain’t broke, don’t fix it.” “And I might say you don’t mess with success” was cited in print in 1964. It does not appear that any one person coined or popularized the simple rhyme.
 
The saying was popularized in the 1960s. “Sign on the desk of a busy, busy TV executive: ‘Don’t Mess With Success’” was cited in 1966.
 
 
6 February 1964, The Berkshire Eagle (Pittsfield, MA), “Civic Assn. Meeting,”  pg. 19, col. 3:
“And I might say you don’t mess with success.”
(Wendell Butler, planning board member.—ed.)
 
11 May 1966, Boston (MA) Traveler, “Wonderland Opens 100-Night Season” by Bill Liston, pg. 53, col. 1:
Wonderland officials don’t like to mess with success and the Revere Oval is the most successful in the nation.
 
13 May 1966, San Diego (CA) Union, “Point of View” by Donald Freeman, pg. A24, col. 1:
Sign on the desk of a busy, busy TV executive: “Don’t Mess With Success.”
   
Google Books
TV Guide
1966
Pg. 132:
Unafraid to mess with success, Lee Rich decided to bring the show home from Spain and shoot it on a soundstage at Metro with a four-day shooting schedule: two days on the stage and two on local location.
 
6 February 1968, Richmond (VA) Times-Dispatch, “Saints Seek Second Win Over Cougars Tonight” by Bill Millsaps, pg. C-3, col. 3:
You don’t mess with success.
   
Google Books
Technograph
Volume 85
1969
Pg. 62:
There’s a wise old proverb that goes: “Don’t mess with success!’
   
Google Books
Cars & Trucks
Volume 49
1977
Pg. 37:
There’s an old business axiom that says, “Don’t mess with success!”
 
OCLC WorldCat record
JEEP GRAND CHEROKEE: Don’t mess with success
Author: Daniel Charles Ross
Publisher: [New York, N.Y. : Ziff-Davis Pub. Co.,
Edition/Format: Article Article : English
Publication: Car and driver. 41, no. 4, (1995): 80
Database: ArticleFirst
   
OCLC WorldCat record
Antiretroviral rounds. Should we mess with success?
Edition/Format: Article Article : English
Publication: Journal watch. AIDS clinical care, 2009 Aug; 21(8): 63-5
Database: From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.