have rocks in head

have rocks in (one's) head

To be thoroughly stupid, crazy, absurd, incorrect, etc. You must have rocks in your head if you think the bank will approve you for another loan.See also: have, head, rock

have rocks in one's head

Fig. to be silly or crazy. John is a real nut. He has rocks in his head. I don't have rocks in my head—I'm just different.See also: have, head, rock

rocks in one's head, to have

To say or do something crazy, ridiculous, or stupid. This slangy expression, often used in a not very polite response to a bizarre statement or action, dates from about 1940. Presumably it accuses the person of having rocks instead of brains, as in “Drive all of two blocks to get the paper? Do you have rocks in your head?” See also: have, rock