no fool like an old fool, there's

(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

no fool like an old fool, there's

An old fool is the worst kind of fool, as in He's marrying a woman fifty years his junior-there's no fool like an old fool. This adage, now considered somewhat offensive for stereotyping old people, appeared in John Heywood's 1546 proverb collection and has been repeated ever since.
See also: fool, like, no, old