To fire a bullet into the heart or brains of one's fellow man even a fellow man striving to do the same to you creates what might be called an unassimilable memory: a memory that floats on daily life the way an oil stain floats on rainwater. Stir the rain barrel, scatter the oil into countless drops, disperse it all you like, but it will not mix; and eventually the slick comes back, as loathsomely intact as it ever was.