A statement that indicates a person is
not all there. The happy meal is symbolic of a well rounded, mentally healthy
individual. However, being a few fries short, the
happy meal isn't quite as happy, and may well be
mentally disturbed. Frequently used when someone does something very odd or otherwise demonstrates
abnormal mental capacity. For example:
Guy 1: Did you see Richard Simmons on Leno last night?
Guy 2: Yeah, he's a few fries short of a happy meal.