Not have all (one's) marbles phrasal verb negative informal
The expession "not have" can be substituted by the verb "lose".
Said when you are in a mental state of being unbalanced, unstable.
After breaking up, she does not have all her marbles.
After talking to my best friend, I worried that he did not have all his marbles.
If you sleep deprived, you will not have all your marbles.
To be mentally deficient or incompetent; to become of mental health disorders
A way of acting or thinking that achieves a healthy balance between two extremes
If someone is not right in the head, he or she doesn't have a normal mental state or condition.
To become stupid, foolish, silly or crazy
Not to do too much or too little in anything
The verb "have" should be conjugated according to its tense.
After being informed that Peter failed the exam, he has not had all marbles.
The origin of this expression is not clear.