I saw Joel and Ethan Coen's A Serious Man this morning, and aside from thinking it is one of their best films, I also felt the movie explained a lot about the cynicism and detached attitude that permeates their entire body of work.
A Serious Man is the first movie by the Coens that is based on anything remotely autobiographical, and it is also the first film in which they grapple with their Jewish heritage and upbringing. This is why the movie, although just as bleak and unforgiving as their other comedies, also feels more heartfelt and personal. After seeing it, you understand the Coens' previous films a little better (even Barton Fink). The ending alone - which is pretty stunning - encapsulates everything they've always expressed in their films in a neat 60 seconds.
I've never interviewed the Coens before, but I'll talking to them via telephone for a few minutes tomorrow. The fact that they are doing phone interviews for A Serious Man is another indication, I think, of how this one means a little bit more than usual to them.