Divide by Zero
The Living Force
I just finished watching this movie and had the same feeling as Heimdallr and cagoule.
As I interpreted it, he was insane from the beginning and in the end he acknowledged what he had done but simply couldn't live with it. So he decided for lobotomy, as he said: "better to die as a good man" (as in, he dies as the good personality he had created for himself), then to continue living with his memories as a monster (Andrew who had killed his wife).
I suppose some of us assumed he was sane, sensing some kind of conspiracy going on with the environment.
Please do check out this video: http://vimeo.com/13398426 SHUTTER ISLAND: AN ARGUMENT FOR SANITY
Some of the clues that he points out in this video are amazing! One very suspicious question: why would the "insane" woman he interviewed later turn up as a nurse?!?