You've got rocks in your head
Suggest a CorrectionMeaning
You are showing very poor judgment or proposing something the speaker considers foolish. A blunt insult to someone's judgment or intelligence. It can be playful among people who know each other well, but it is inappropriate as a serious description of disability or mental health. Regional use: Chiefly American informal English.
Origin
Have rocks in one's head is American slang documented from the 1940s. The image treats rocks as useless substitutes for brains, so the person's poor judgment is attributed to a head filled with the wrong material. The exact inventor and first occasion are unknown. There is no evidence tying this wording specifically to Australia or to the medieval stone-of-folly motif, and neither connection should be asserted without documentation.
Research Sources
Variants
- Have rocks in one's head
- Rocks in your head
Usage Examples
- You've got rocks in your head if you plan to cross the desert without carrying water.
- When I suggested selling the house on a whim, my brother asked whether I had rocks in my head.
- She said the investors must have rocks in their heads to accept those terms.