Yeah I would have to say that there were a a few people here that any of the below would apply to.
Few fries short of a happy meal.
Not playing with a full deck.
Elevator doesn't go all the way to the top.
Few eggs short of a dozen.
Not the brightest bulb to ever burn.
Not the sharpest tool in the shed.
Few stands off bottom. (Oilfield term)
Few cans short of a six pack.
When they leave home they are depriving their village of an idiot.