Quoted elsewhere: It is a venerable chestnut

Why is old, oft-retold story called a chestnut?

(Heck, for that matter, why is the nut itself called a "chest" nut?))

I know zmj (and others) don't think much of this source, but ...
http://www.etymonline.com/index.php?term=chestnut

From Lippencott's Monthly Magazine: the joke mentioned in the Etymonline entry. (Begins at the bottom of the page and continues on the next for the punch line.)

Well, arnie, I like etymology.com. It at least can get you started when you are wondering about the origin of a word.

I found something strange in the Online Etymology Dictionary, talked to the editor, and got it changed.