Lost quickly became an incredibly popular series that fans obsessed about. The story of survivors of a plane crash ending up on a mysterious island captured imaginations almost immediately. Endless theories about what was really going on flowed across the internet, most of which turned out to be untrue.

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Unfortunately, the show didn't provide many concrete answers. The same fans who helped rocket Lost to the top of the ratings were incredibly unsatisfied with the final season, particularly the series finale. Few answers were provided, and the few that were didn't seem to make a lot of sense.

10 The Bomb

At the end of season five, Jack and friends detonated a bomb in the past that presumably destroyed the island or, at the very least, changed things so the plane crash never happened.

Fans came to this conclusion when the sideways timeline appeared in season six, showing those who crashed going about their regular lives with no memories of the island. The bomb didn't destroy the island but the confusing part was that the impact of the bomb never came up again. It didn't seem to accomplish anything.

9 Desmond

While all the people on the island had some sort of connection to it, Desmond's seemed particularly strong. He was not on Oceanic Flight 815. Instead, he was shipwrecked on the island three years earlier as part of Jacob's grand plan to defeat the Man in Black.

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Because of this, Desmond appeared to have a greater affinity to everything going on and an almost instinctual understanding of it all. By the finale, the character had become a deux ex machina with knowledge that he should not have had to push the story forward. Desmond was still a great character, though.

8 The Dog

Vincent the Yellow Lab was one of the most confusing, and adorable, parts of Lost. He was on the plane accompanying Walt, a young boy who was briefly on the island before escaping with his father. Vincent was left behind. He was there the moment Jack woke up on the island in the pilot and was there when Jack died in the finale.

But how this dog continued to survive and where he was for the long periods he was not on screen is confusing. There were all kinds of theories that Vincent was a lot more than he appeared to be, though that happened a lot in this series.

7 Walt

Then there's Walt, one of the biggest red herrings in Lost. Early on in the series, the child appeared to have incredible powers developing. Fans assumed this would be a huge plotline moving forward. Instead, the character left at the end of season two and made sporadic appearances over the next couple of seasons.

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No further explanation of his powers was given. Fans hoped for an appearance in the series finale but nothing came of this. It felt like a missed opportunity to reconnect to the earlier episodes and give a small amount of resolution to a dropped plotline.

6 The Sideways Timeline

As part of season six, the sideways timeline was introduced. It featured all of the same characters but not on the island. They lived relatively normal lives, presumably what would have happened to them if they hadn't been marooned.

At the same time, a timeline was playing out on the island that featured the continuing battle against the Man in Black. Fans were stymied by the finale at first but eventually worked out that the sideways timeline was limbo and what happened on the island did happen. The finale this led to was still incongruous with the rest of the series.

5 Religious Undertones

What surprised a lot of fans with the final reveal were the religious components to it. While there had been religious undertones throughout the series from early on, they intensified in season six and even more so in the finale.

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The final moments featured the majority of the characters, dead and meeting up in a church after realizing the sideways timeline was limbo. They then moved on to the afterlife together. The moment was a lot less science fiction and a lot more religious than expected. The sudden change in tone was confusing for many fans.

4 Everyone Was Dead But They Weren't

Part of the problem was related to the idea that two separate stories were happening at the same time, one where the survivors were dead and another where they weren't. A long-standing theory among fans was that everyone died when the plane crashed in the pilot and everything that happened since was in purgatory.

That ultimately wasn't the case, but having a second timeline running at the same time as the main timeline, where they were dead, confused the issue. The choice to have a finale that could easily be confused with a popular but incorrect fan theory was odd, to say the least.

3 Missing People

One of the strangest parts of the final scene was how many characters didn't seem to make the cut. Again, fan-favorite red herring Walt was not there, though that might be simply because he was younger than the rest and hadn't died yet.

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His father, Michael, was also missing though his spirit was reputedly trapped the island due to the crimes he committed there. Mr. Eko also wasn't around, possibly because he had already made peace with his life and moved on. There were a lot of familiar faces missing from those final moments and no clear reason why they weren't there.

2 So Many Unanswered Questions

Depending on your perspective, the biggest sin of the finale was how many questions were left unanswered. Lost was a series filled with mysteries, some of them requiring more explanation than others.

In the end, many of them were never resolved in the slightest, leaving fans with more questions than they would have liked. Not every mystery needs a solution, and the answers fans did get were often unsatisfying. The finale was one last chance to give some sort of closure.

1 Guys, Where Are We?

The biggest question that was never truly answered was posed at the end of the pilot when Charlie says, "Guys, where are we?" Over the next several seasons, Lost seemed to struggle with that line, not only what the answer was but if the series even wanted to answer it.

No fan would be surprised to find out that no one behind the scenes on Lost knew what was going on. For anyone invested in the entire series, this was the ultimate question, the answer to which may have given them everything they needed from the show. To not try to answer it was confusing at best.

NEXT: 10 Unanswered Questions We Still Have About Lost