not have all (one's) marbles

not have all (one's) marbles

To not be completely mentally sound or stable. After he started bringing conspiracy theories into the conversation, I started wondering if maybe he didn't have all his marbles. It's easy to feel like you don't have all your marbles when you're that sleep deprived.See also: all, have, marble, not

not have all one's marbles

Fig. not to have all one's mental capacities. John acts as if he doesn't have all his marbles. I'm afraid that I don't have all my marbles all the time.See also: all, have, marble, not