take leave of
Also, take one's leave of. Depart from, say good-bye to. For example, Sorry but I have to take leave of you now, or After the movie we'll take our leave of you. [Mid-1200s]
take leave of one's senses. Behave irrationally, act crazy, as in Give them the keys to the house? Have you taken leave of your senses? [Late 1800s] Also see come to one's senses.