Teen movies often have an unspoken underlying premise in which high school is seen as less serious than the adult world. But when your head is encased in that microcosm it's the most serious time of your life.

All of Koons's best art - the encased vacuum cleaners the stainless-steel Rabbit (the late-twentieth century's signature work of Simulationist sculpture) the amazing gleaming Balloon Dog and the cast-iron re-creation of a Civil War mortar exhibited last month at the Armory - has simultaneously flaunted extreme realism idealism and fantasy.