Definition & Meaning of "lose one's marbles"

What is the origin of the idiom "lose one's marbles" and when to use it?

The exact origin of the phrase "lose one's marbles" is uncertain, but it is believed to have originated in the early 20th century, possibly in the United States. The phrase draws on the metaphor of marbles, small glass balls used in children's games, to represent one's mental faculties or sanity. It can be applied to instances where someone appears to be detached from reality, makes nonsensical statements, or demonstrates erratic thinking. Additionally, this idiom can be used to describe age-related cognitive decline or moments of extreme stress or emotional strain that impact one's mental well-being.