The brothers’ art took a quantum leap with “No Country,’’ in which they brilliantly mimicked another man’s nihilism, that of author Cormac McCarthy. With this film they bring it all back home. “A Serious Man’’ is, above all, a memory play, and the closest we may ever get to a personal memo from the Coens. They grew up in the Minneapolis suburbs and have acknowledged that Larry is in character and spirit close to their father, which of course makes 13-year-old Danny Gopnik their own stand-in.