“Success depends on the second letter”

“Success (all) depends on the second letter” is a motivational adage that has been printed on many images. The saying has been cited in print since at least 1992 and is of unknown authorship.
 
     
Google Books
The Art of Successful Teaching:
A Blend of Content & Context
By Tim Lautzenheiser
Chicago, I: GIA Publications, Inc.
1992
Pg. 214:
“Success depends on the second letter.”
 
Google Groups: rec.arts.marching.band.high-school
Quotes to Live By ‘98 Season
MKrek
7/7/98
(...)
Success depends on the second letter. (Now that’s self-explanatory)
 
Google Groups: rec.arts.marching.band.high-school
marching band quotes
AliciaBeth
4/11/01
(...)
Success depends on the second letter.
 
Twitter
Erwin Mcken
‏@bigwavedude
The secret to your own success is found in the second letter of the word     SUCCESS.
6:51 PM - 29 Sep 2009
 
Twitter
❤️Nisha Baby ❤️
‏@NishaYvette
Postive Quotes: Success depends on the second letter.
8:43 AM - 14 Oct 2009
 
Everyday Power blog
December 26, 2014
20 Awesome Inspirational Quotes with Pictures About Success and Determination
By Jeffrey I. Moore
(...)
Success all depends on the second letter. It’s all in U!
   
My Status Wishes
March 2015
{Updated} 100 Best Whatsapp Status, Quotes And Ideas
(...)
“Success” all depends on the second letter
     
Google Books
From the Corner to the Corner Office:
A Blueprint for Success
By James A. Barlow
Lulu Publishing Services (Lulu.ccm)
2016
Pg. 44:
Success depends on the second letter. —Anonymous