one's marbles

Noun

colloquial figuratively plural plural-only

(colloquial, figuratively) One's sanity; one's mental faculties.

Japanese Meaning

正気（理性や精神の健全な状態を指す） / 精神活動（思考力や記憶力などの能力）

The endless meetings were enough to make anyone lose one's marbles.

終わりのない会議は、誰でも正気を失いかねないほどだった。

Sense（1）

(colloquial, figuratively) One's sanity; one's mental faculties.

I don't think he's got his marbles.