馬ば鹿かにつける薬くすりはない

expression, i-adjective

there is no cure for stupidity; a born fool is never cured

Proverb meaning that foolishness or stupidity cannot be fixed, just as there is no medicine for it. Often used resignedly or humorously.

• 何なん度ど注ちゅう意いしても同おなじ失しっ敗ぱいをするなんて、馬ば鹿かにつける薬くすりはないね。

  He makes the same mistake no matter how many times I warn him—there's no cure for stupidity.

• あいつがまた騙だまされたのか。馬ば鹿かにつける薬くすりはないな。

  He got fooled again? There's no medicine for fools.