Carol Weston? Anonymous?
Quote Investigator: The author Carol Weston has been providing advice to young women as a columnist in “Girls’ Life” magazine since the 1990s. Even before that in 1985 she wrote “Girltalk: All the Stuff Your Sister Never Told You” which included the following guidance. Boldface added to excepts by QI:[ref] 1985, Girltalk: All the Stuff Your Sister Never Told You by Carol Weston, Chapter 2: Friendship: You Don’t Like Everybody; Why Should Everybody Like You?, Quote Page 47, Barnes & Noble Books: A Division of Harper & Row, New York. (Verified with hard copy) [/ref]
The best way to accept a compliment is to smile and say. “Thank you.” If you like, you can add, “That’s nice of you to say.”
Beware of fishing for compliments—you might come up with a boot!
Below are additional selected citations in chronological order.
In 1989 “Words of Wisdom: More Good Advice” compiled and edited by William Safire and Leonard Safir contained an entry for the quip crediting Weston:[ref] 1989, Words of Wisdom: More Good Advice, Compiled and edited by William Safire and Leonard Safir, Topic: Praise, Quote Page 294, Simon and Schuster, New York. (Verified on paper)[/ref]
Beware of fishing for compliments—you might come up with a boot.
— Carol Weston
In 1994 “The Republic” newspaper of Columbus, Indiana printed the joke with an ascription to Weston as a “Thought for the day”.[ref] 1994 August 1, The Republic, Column One: Thought for the day, Quote Page 1, Column 1, Columbus, Indiana. (Newspapers_com) [/ref]
In 1997 an advertisement in an Ottawa, Canada newspaper printed a slightly altered anonymous instance of the quip. The word “might” was changed to “may”:[ref] 1997 March 11, The Ottawa Citizen, (Joke displayed in a box within an advertisement for Princess Auto), Quote Page 8 of Advertisement, Ottawa, Ontario, Canada. (Newspapers_com) [/ref]
Beware of fishing for compliments — you may come up with a boot
In conclusion, Carol Weston should receive credit for this remark based on the 1985 citation.
Image Notes: Image of a fisherman in a boat from mydaydream at Pixabay.
(Great thanks to the anonymous person whose inquiry led QI to formulate this question and perform this exploration.)