From Longman Dictionary of Contemporary Englishtake leave of your sensestake leave of your sensesCRAZYto suddenly start behaving in a strange way You want to marry him? Have you taken leave of your senses? → leave
Examples from the Corpus
take leave of your senses• Her daughter had taken leave of her senses and her husband was never at home when he was needed.• She had taken leave of her senses!• You must have taken leave of your senses! b. You must have left your senses behind! 35a.• But frequently they appear to have taken leave of their senses when it comes to choosing the right sort of women.• But John had not taken leave of his senses.• Was she taking leave of her senses?• I know what you're saying and I think you've taken leave of your senses.• You challenged him to a fight? Have you taken leave of your senses? 