Robert Frost? Lillian Russell? Fliegende Blätter? Evan Esar? Anonymous?
Question for Quote Investigator: An old-fashioned quip about vanity and aging states that a diplomat always remembers a person’s birthday but never remembers a person’s age. This joke has been attributed to the famous U.S. poet Robert Frost, but I have been unable to find a solid citation. The subject of the jest is usually a woman. Would you please explore this topic?
Reply from Quote Investigator: The earliest match for the core of this joke located by QI appeared as a filler item in a Rochester, New York newspaper in May 1896. The remark was ascribed to a German humor magazine called “Fliegende Blätter” (“Flying Pages”). A diplomat was not mentioned in this version. Boldface added to excerpts by QI:1
Husband — Strange, but my wife always wants me to remember her birthday, but to forget her age.—Fliegende Blatter.
Another instance of the joke appeared as a filler item in a Monmouth, Illinois newspaper in June 1896:2
Many a woman wants her husband to remember her birthday but to forget her age.
Yet, another instance appeared in a Mount Carmel, Pennsylvania newspaper in July 1896:3
It is safe to remember a woman’s birthday, provided you forget her age.
In 1912 a newspaper in Knoxville, Tennessee4 and papers in several other locations5 printed an anecdote in which the prominent actress Lillian Russell received credit for a version of the joke using the word “diplomat”:
Miss Lillian Russell, more beautiful than ever, was serving tea at the Professional Woman’s League bazaar at the Waldorf-Astoria. A member of the Spanish legation passed with two charming girls, and Miss Russell said.
“No wonder that young man is so popular with the ladies. He is a ladies’ diplomat.”
“How a ladies’ diplomat?” a composer asked. “Well,” explained Miss Russell, “he is the sort of chap who always remembers a woman’s birthday and forgets her age.”
Many years later in 1939 after the quip was already in circulation it was attributed to Robert Frost. Thus, the linkage to Frost was very weak.
Additional details and citations are available in the article on the Medium platform which is located here.
Images Notes: Illustration of a birthday cake from Deva Williamson at Unsplash. The image has been cropped.
Acknowledgement: Great thanks to Brian whose inquiry led QI to formulate this question and perform this exploration. Thanks also to researcher Barry Popik for his pioneering work on this topic. Popik found citations beginning in 1913 together with attributions to Frost by 1949.
 1896 May 10, Democrat and Chronicle, (Filler item), Quote Page 8, Column 5, Rochester, New York. (Newspapers_com)
 1896 June 11, Warren County Democrat, (Filler item), Quote Page 10, Column 4, Monmouth, Illinois. (Newspapers_com)
 1896 July 15, Daily News, Selected Items: That Will Prove Interesting Reading for Daily News Patrons, Quote Page 3, Column 4, Mount Carmel, Pennsylvania. (Newspapers_com)
 1912 February 4, The Journal and Tribune, Section: The Woman’s Page, A Ladies’ Diplomat, Quote Page 3A, Column 4 and 5, Knoxville, Tennessee. (Newspapers_com)
 1912 March 1, The Gothenburg Times, Ladies’ Diplomat, Quote Page 6, Column 6, Gothenburg, Nebraska. (Newspapers_com)