lose your marbles
失去理智或心智不健全
口語·形容某人行為古怪或精神失常
英文釋義
to lose one's mind or sanity; to become mentally unstable
例句
Grandpa started talking to his plants again; I think he's losing his marbles.
典故來源
源自20世紀初的俚語，'marbles'指代理智或頭腦，失去彈珠比喻失去心智。