What Does The Ending Of Shutter Island Really Mean?

Ending Theory #4: The Film Is Andrew's Lobotomised Nightmare

Given the lead character's fragile state of mind, and the film's heightened sense of reality, what's to say the whole thing isn't just all an intense nightmare? Furthermore, given its ludicrous nature, what's to say Shutter Island isn't the drooling daydream of the newly lobotomised Andrew Laeddis, as he remembers his past leading up to his lobotomisation in fragments, with nightmarish dream imagery included? There are hints throughout the film at this - even outside Teddy's 'official' nightmares, where blood flows freely and bodies come stacked on top of one another, OTT horror symbology abounds. Rat infestations, grabbing arms feeling through walls, extreme weather - crashing thunder and lightning included - and haunted houses all feature prominently. Then there's the less obvious stuff, where the 'dream' bleeds into what is supposed to be 'reality'. Take a closer look at 'Teddy' and 'Chuck's interrogation of Mrs. Kearns, the woman who requests a glass of water, then appears to proceed to drink it straight down - only the cup has disappeared, and she's drinking out of an empty hand. Andrew is lobotomised at the end of Shutter Island, there's no disputing that - but what if it's already happened by the time the film begins, and the movie you're about to see is the scrambled assembly of thoughts from someone whose mind no longer functions properly? Teddy's vision halfway through the film of 'Laeddis' with an ugly scar across his face, possibly suggesting a lobotomy, could be a reminder for Andrew that he's already undergone the procedure. What does the ending of Shutter Island mean to you? Let us know in the comments below.