An insult that is not, of course, implying that the person on the receiving end of said insult has a brain that is held together by paste. It is just another way of calling somebody 'stupid'.
Carl: Well, how was I supposed to know that the coffee was scalding hot?
Pete: You made the coffee, paste-for-brains.
Pete: You made the coffee, paste-for-brains.
by Diggity Monkeez January 26, 2005