Off one's rocker
Meaning
To be crazy, insane, or mentally unsound.
Origin
Imagine a person rocking gently in a chair, a picture of calm and composure. The 'rocker' here refers to the curved runners on which a rocking chair rests. Now, picture that person somehow becoming 'off' those runners—tipped over, unbalanced, no longer stable. This vivid image of losing one's equilibrium, dating back to the late 19th century in America, neatly captured the idea of losing one's mental balance, descending into madness or irrationality. It's a delightful metaphor that turns a simple piece of furniture into a symbol of sanity's precarious grip.
Examples
- When he suggested we paint the entire house purple, I thought he'd gone completely off his rocker.
- After pulling an all-nighter for the exam, she felt like she was off her rocker and couldn't think straight.