I am in favor of all takes and discussion of what I agree with Arthur Miller called the single most important thing to try and understand about the 20th century. This story is, on the surface, a character study of a descent into madness, although without any back-story to the main character, a lot is asked of the audience to follow him down the rabbit hole. The more effective exploration is perhaps the subjects of history and memory that are argued by the various characters our 'protagonist' encounters.
The authors of the film may maintain that their story's ending is deliberately undefined (there is no Commentary on the DVD), but I usually get the feeling in cases like this that they boxed themselves into a corner they couldn't find a way out of - and perhaps that's also the reason for the lack of a history for Lukas. That said, it is an extraordinary film, and I intend to read the book it was based on.
