lose one's mind

Idioms  

1. Also, lose one's reason. Go crazy, lose one's sanity, as in I thought she'd lost her mind when she said she was going ice-fishing, or That assignment is enough to make me lose my reason. The first expression dates from the late 1500s; the second employs reason in the sense of “unimpaired mental faculties,” a usage dating from the late 1300s. Also see under go out of one's mind; have all one's buttons.

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Example Sentences

A mind is a terrible thing to waste," he lost himself in a self-indicting verbal fog: "What a waste it is to lose one's mind or not to have a mind.

From Time Magazine Archive

To lose one's mind is a dreadful affliction, but not to know that one is crazy is even worse.

From Grace Harlowe's Second Year at Overton College by Flower, Jessie Graham [pseud.]

She leaned her head down on her father's shoulder and thought how sad it must be to lose one's mind.

From A Little Girl in Old New York by Douglas, Amanda Minnie