During its six season run, Lost became a ratings juggernaut that captured the imaginations of viewers. It is part of the cultural lexicon, a defining show of early 2000’s television. Unfortunately, it produced an series finale that was open ended and did little wrap up the overall plot. Obsessive fans have spent the last decade dissecting every scrap of information they came across, hoping to find that one puzzle piece that brings everything into focus. But even while Lost was on the air, fans came up with some inventive theories, the most entertaining of which came from Jeff Jensen at EW.

FALSE: It Was All A Dream

Much of what happened on the island was confusing mashup of various sci-fi concepts, religion and unexplained iconography. As such, many fans started speculating that is all might  have happened in the dreams of one of the characters. A popular choice was Hurley as he was a definitive fan favorite. That theory never panned out as there were too many moving parts for it to work. Plus, the castaways’ adventures were not confined to one location. Hurley’s dreams would have to be pretty detailed about events and people he had nothing to do with.

FALSE: Two Smoke Monsters

One of the most stunning visuals was the smoke monster that tormented everyone living on the island. It was supposedly a form taken by Jacob’s brother in an attempt to escape his prison.

But some fans believed there was a second smoke monster responsible for many of the more horrific acts committed by the entity. An even smaller sub-group of those people speculated that the second smoke monster might actually be The Devil. There are few clues and virtually no hard data to back that up but it is an intriguing thought.

FALSE: The Dharma Initiative Created Hurley

As the theory goes, “Hurley” was some sort of super intelligence created by the ominous Dharma Initiative for some unknown purpose. It escaped their grasp, finding refuge inside of a human in a psychiatric institution named Hugo Reyes. The Dharma Initiative then broadcast the mysterious series of numbers in an attempt to lure Hurley and its human host back to the island, which happened when Oceanic Flight 815 crashed.  There’s no evidence to support this idea whatsoever other than mysterious and powerful nature of the Dharma Initiative.

FALSE: Walt Is Matthew Abaddon

One survivor of the plane crash was Walt Lloyd, the ten-year-old son of Michael. The only child survivor, Walt was depicted as unique and possibly having some sort of mystical or superhuman abilities. The problem is kids grow up, which doesn’t work well on a series that takes multiple episodes for a day to pass by. The actor aged out of the role quickly and was written off the show.

One fan theory posits that Walt grew up to be another mysterious character named Matthew Abbadon, though the only supporting evidence is that both characters are black.

FALSE: Sharing The Island

As Lost went on, time travel and its impact on the narrative played an increasingly important role. When the Oceanic Six, the survivors found alive by authorities in one season, return to the island, they end up travelling far back in time before they ever crashed. The theory is that both the past and present survivors are on the island at the same time. Well, to an extent, at least. The mysterious whispers the present survivors often hear in the woods might just be echoes of their past selves chatting with each other.

FALSE: Location. Location. Location.

The exact location of the island is massive mystery itself, especially considering you need to approach it from a perfect direction to get to it. One theory is that the island is located in the Arctic, protected by a tropical pocket climate hidden there. Planes and boats accidentally access it by passing through portals that transport them to it.

But in the show, its made clear that the island actually moves locations, jumping between various points like the Mediterranean Sea and the South Pacific. It might have been in the Arctic at one point but that isn’t its permanent location.

FALSE: The Island Is A Laboratory

As an ecosystem, the island makes little or no sense. It appears, at first, to be a standard tropical island with the requisite flora and fauna. But after you spend enough time there, as the survivors of Oceanic Flight 815 did, you start noticing that things don’t add up. Weather, tides and more do not operate the way they are supposed to. Coupled with all the Dharma Initiative research stations, many have come to believe that the island itself is a constructed laboratory. The problem with that is it flies in the face of the theory that the island was created by an unknown entity to control powerful forces.

FALSE: The Time Loop

Time travel became such a hug part of the series that it infected many fan theories. A big one was that many of the show’s key characters were in a time loop, that they would continually return to certain points and go around again.

While this would have required a lot of explaining to work, it did at least give a reason for characters healing miraculously, knowing more than they should or showing up somewhere strange. It was a huge theory but one that had huge potential.

FALSE: Big Collisions

There is a scientific hypothesis that the Moon was formed when an astronomical body the size of Mars collided with the Earth. There’s a Lost fan theory that says the island exists at the point of impact. To take it a step further, a magnetic core left by the body generates a field that protects the island. This field might repel water to form the island on the ocean floor as well as play a part in keeping it invisible to the rest of the world. Planes and ships get to the island through holes in the field.

TRUE: Purgatory

To be honest, this one is only true to an extent but it’s as close as your gonna get with Lost. Fans had long believed that everyone on Oceanic Flight 815 died in the plane crash and that the island was purgatory. There actually was some truth to this one. While they didn’t die in the crash, they did die over time on the island, all experiencing version of purgatory in season six as they moved on to the next phase of existence together. It was a more spiritual and less sci-fi ending than many fans were expecting.