“Do not regret growing older. It is a privilege denied to many” is a saying that has been printed on many posters. “Be glad to grow old; it’s privilege denied to many” was printed on the front page masthead of the Gettysburg (PA) Times in 1952. “Do not regret growing old. It is a privilege denied to many” was cited in several 1959 newspapers. Authorship is unknown.
 
“Do not resent growing old. It is a privilege denied to many” was published in the syndicated “Dear Abby” advice column in 1964, popularizing the expression.
     
 
25 June 1952, Gettysburg (PA) Times, pg. 1, right masthead:
GOOD EVENING
Be glad to grow old; it’s privilege denied to many.
 
12 September 1953, Illinois State Journal (Springfield, IL), “Making Conversation” by J. Emil Smith, pg. 4, col. 2:
Why regret growing old, when so many people don’t have that privilege?
 
Old Fulton NY Post Cards
18 December 1958, The Livingston Republican (Geneseo, NY), “Log Grindings” by Gerald Saddlemire, pg. 4, col. 3:
Given the proper attitude and community assistance the older person can well subscribe to Mr. Brink’s closing statement “Do not regret growing old. It is a privilege denied to many”.
 
31 August 1959, Ukiah (CA) Daily Journal, “Spot Light” by H. M. Ivey,  pg. 1, col. 1:
Do not regret growing old. It is a privilege denied to many.
 
30 September 1959, Altoona (PA) Mirror, “Poet’s Corner,” pg. 27, col. 2:
OLD AGE
It is a privilege denied to many,
(...)
THOMAS M. BARD
 
Google News Archive
3 October 1959, Pittsburgh (PA) Press, “The Scoreboard” by Lester J. Biederman, pg. 6, col. 1:
LOS ANGELES, Oct. 3—Final diary of the season of a baseball writer who thanks Bob Schulz for the following observation: “Do not regret growing old; it is a privilege denied to many.”
   
4 January 1960, The Daily Gleaner (Kingston, Jamaica), pg. 5, col. 1 ad:
Do not regret growing old. It is a privilege denied to many.”
(...)
The Life Assurance Companies in Jamaica
 
Google News Archive
25 May 1960, Reading (PA) Eagle, “As Seen by Her” by Lily March, pg. 26, col. 1:
How about putting this on file in your mind?
 
“Never regret getting old. It is a privilege denied to many.”
 
28 January 1964, Greensboro (NC)

, “Dear Abby” by Abigail Van Buren, pg. A9, col. 1:
CONFIDENTIAL TO “BUFFALO BILL”: Do not resent growing old. It is a privilege denied to many.
 
3 March 1964, The Oregonian (Portland, OR), “Dear Abby” by Abigail Van Buren, sec. 4, pg. 2, col. 8:
DEAR ABBY: The item in your column, “Confidential to Buffalo Bill: Do not resent growing old. It is a privilege denied to many” hit me hard, Abby. I am a 26-year-old widow with two small children, 6 and 8. My husband was 27 years old when he died of electric shock at his job, If people only knew how lucky they were to have each other!
HEARTBROKEN IN BATAVIA, N.Y.
 
7 May 1967, The Evening Star (Washington, DC), This Week magazine, cover page:
THIS WEEK’S WORDS TO LIVE BY:
“Do not complain about old age. It is a privilege denied to many.”
—ANONYMOUS
 
24 April 1980, Augusta (GA) Chronicle, Ann Landers syndicated advice column, pg. 14B, col. 1:
DEAR ANN: (...) On my kitchen wall hangs a small plaque. I thank God everyday I can wake up and read it. The message is as follows:
 
“Don’t regret growing old. It’s a privilege denied to many. Sign me—GRATEFUL FOR EVERY DAY IN HAMMOND, IND.
 
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Do not regret growing older.  It is a privilege denied to many.  ~Author Unknown
8:10 PM - 21 Jun 2015