nobody's fool

noun

(set phrase) A person who is not easily deceived or victimized; one who is perceptive, clever, or thoroughly common-sensical.

He may seem naive, but he's nobody's fool.

意味（1）

(set phrase) A person who is not easily deceived or victimized; one who is perceptive, clever, or thoroughly common-sensical.

Also, he is nobody's fool. He possesses the brain and strength of character to play his part.