have all marbles
have all (one's) marbles
To be mentally sound or stable. Now that I've gotten a good night's sleep, I'm starting to feel like I have all my marbles again. Grandma still has all her marbles, in spite of her other health problems.
have all one's marbles
Fig. to have all one's mental faculties; to be mentally sound. (Very often with a negative or said to convey doubt.) I don't think he has all his marbles. Do you think Bob has all his marbles?