no fool like an old fool

(there's) no fool like an old fool

An older person who makes foolish decisions is especially at fault, as experience should have taught them not to do such things. My grandfather got caught trying to buy weed from some kids in the neighborhood. No fool like an old fool, eh? There's no fool like an old food—what did you think would happen if you tried to hide your profits to avoid the taxes?
See also: fool, like, no, old
Farlex Dictionary of Idioms.

(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, no, old
Farlex Partner Idioms Dictionary

there's no fool like an old fool

Foolishness does not abate with age. This observation was already a proverb when John Heywood amassed his 1546 proverb collection. It has been repeated ever since.
See also: fool, like, no, old
The Dictionary of Clichés by Christine Ammer
See also:
  • (there's) no fool like an old fool
  • a fool and his money are soon parted
  • fool and his money are soon parted
  • fool and his money are soon parted, a
  • parted
  • doofus
  • be heading for a fall
  • musclehead
  • experience is the teacher of fools
  • dearly
References in periodicals archive
THERE'S no fool like an old fool - and Sir Bernard Ingham, former chief Press secretary to Margaret Thatcher, has certainly shown himself to be one.
Some people never learn; ECHO
NO fool like an old fool - especially a rich old fool like sleazy Dragons' Den hardman Duncan Bannatyne.
JOLIE BAD SHOW.
Another adage comes to mind in this case: 'there's no fool like an old fool'.
'BETTER an old man's darling [...]
As the old saying goes: "There's no fool like an old fool".
Letter: Your say - Ronnie runs and runs
"I'm starting all over again and people are telling me I'm a fool, but there's no fool like an old fool, I suppose."
STAR TREK COLM TO BE DAD AGAIN
THERE'S no fool like an old fool - especially in Hollywood.
TELLING IT LIKE IT IS: Please act your age