Off One’s Rocker: Origin and Meaning
In British English there are two variations of the same idiomatic expression. Even though off your rocker is still often used in spoken English today, we would be more inclined to use Off your nut or Off your trolley.
– A: What’s Beth up to these days?
– B: Well, she’s completely gone off her rocker and decided to give up her job, sell all her belongings and go travelling round the world for 2 years!