Grosse Fatigue is about a French movie actor, Michel Blanc, and his doppelganger. In light of the recent discussions I've been having on the Internet about how easy it is to pose as someone else, I thought this was somewhat insightful. To me, the moral of this story is "what's good for the goose is good for the gander." However, the movie doesn't exploit this little moral to its full potential.
At times the movie seems to indulge in surreal cinematography, but I don't quite get the point of it. There's also these interviews with the characters thrown in now and then explaining what's happening, making it look like a flashback. The first part of the movie deals with Blanc being put in prison as a result of his doppelganger's activities. The doppelganger then strikes a deal with Blanc, with the idea that Blanc could take some much-needed time-off while the doppelganger attended to business. It doesn't take much imagination to figure out the rest.
The movie really gets interesting when Blanc meets Phillipe Noiret, who has been ousted by his double as well. Noiret then proceeds to give a discourse about how French cinema is dying, thanks to Hollywood. He says "we'll end up becoming mice in their amusement parks." Instead of capitalising on this theme, the ending takes a really illogical and anti-climatic turn.