A thanksgiving saying credited to “anonymous” has been printed on many images:
 
“Thanksgiving is possible only for those who take time to remember; no one can give thanks who has a short memory.”
     
A similar saying—the second line is slightly different—was cited in a 1924 newspaper:
 
“Thanksgiving is possible only for those who take time to remember. No nation can give thanks that has a poor memory.”
 
“Thanksgiving is possible only for those who take time to remember” was cited by itself in a 1952 newspaper, and “No one can give thanks who has a short memory” was cited by itself in a 1965 newspaper. The full and exact combined saying has been popular since at least 2001.
 
   
22 November 1924, Manitowoc (WI) Herald-News, pg. 3, col. 2:
Thanksgiving is possible only for those who take time to remember. No nation can give thanks that has a poor memory.
(Mr. Lewis speaking at St. Paul’s Methodist church.—ed.) 
 
22 November 1952, Evening World-Herald (Omaha, NE), pg. 5, col. 6:
“Thanksgiving is possible only for those who take time to remember.”
Read Psalm 100
THE FIRST LUTHERAN CHURCH
 
16 November 1956, The Journal-Tribune (Marysville, OH), pg. 10, col. 5:
Thanksgiving is possible only for those who take time to remember.
 
24 November 1965, Holland (MI) Evening Sentinel, “Wit and Wisdom,” pg. 4, col. 2:
No one can give thanks who has a short memory.
 
Google Groups: alt.quotations
Thanksgiving Miscellany
Steven K. Robison
11/21/01
(...)
Thanksgiving is possible only for those who take time to remember; no one can give thanks who has a short memory.
 
Google Groups: rec.arts.tv
TAN/ Gobble Gobble Greetings
Donna L. Bridges
11/22/01
(...)
“Thanksgiving is possible only for those who take time to remember; no one can give thanks who has a short memory.” - Unknown
 
29 September 2005, The Weekly Gleaner (Jamaica, NY), “Gleaner honours 46 long-serving workers,” pg. 11:
Rural News Co-ordinator Claude Mills, himself being honoured for 10 years of service, stole the show as he gave the vote of thanks on behalf of all the honourees.
 
“Thanksgiving is possible only for those who take time to remember. No one can give thanks who has a short memory, so today is a good day for all of us who have endured, and who have remembered the small mercies that we have been granted in this life,” he said to approving applause.
   
Google Books
Say It With Style:
Perfect Quotes for Every Card-Making Occasion
Edited by Tanya Fox
Berne, IN: House of White Birches
2008
Pg. 96:
Thanksgiving is possible only for those who take time to remember; no one can give thanks who has a short memory.
—author unknown
 
Twitter
Beatrice Howard jr
‏@qyfgpvjokdjcl21
Thanksgiving is possible only for those who take time to remember; no one can give thanks who has a short memory.—Author Unknown
12:29 AM - 22 Nov 2016