Not playing with a full deck, a nut job, hamsters fell of the wheel, one fry short of a happy meal, one stick short of a package of gum, one card short of a deck of cards, one donut short of a dozen, one brick shy of a full load, lights are on but nobody's home, a dime short of a dollar, a sandwich short of a cut lunch, lift doesn't go to the top floor.(not bright, crazy, simple, naive)