no fool like an old fool

Also found in: Acronyms.

(there’s) ˌno fool like an ˈold fool

(saying) an older person who behaves foolishly appears more foolish than a younger person who does the same thing, because experience should have taught him not to do it: Fred is going to marry a woman thirty years younger than him. There’s no fool like an old fool.
See also: fool, like, old