Some movies are very straightforward. Others leave fans thinking long after the closing credits, as slow burners. Over the years some fans have offered greater room for debate and speculation over deeper meanings and what’s really going on. This is where fan theories come in.

Theories can be based on everything from finding and searching for a way to explain plot holes, to reading a deeper symbolism into things than a plot may initially present. Fan theories can alter the meaning of a film from happy to sad, hopeful to despair, or even change the entire fate of a film’s main character.

Since many writers keep their cards close to the chest when it comes to the plots of their stories, it’s often up to the imaginations of those watching to determine what’s fact and what’s fiction. Here are 20 unusual fan theories about popular films that actually make sense.

7 Jack From Titanic Is A Time Traveller

via Bustle

While many movies have historical inaccuracies, Titanic has many that point to one character, Jack Dawson. Jack says he went ice fishing in manmade Lake Wissota, which wasn’t built until five years after the Titanic sank. The young budding artist also says he sketched portraits near a rollercoaster on the Santa Monica Pier, another attraction that wasn’t built until several years later. Other time traveller hints are his 1930’s style haircut and the bag he carries, also not a popular choice until the 1930s.

Time Traveller theorists say that Jack arrived to stop Rose’s suicide attempt and keep the boat on course to meet its sad destiny.

6 Ferris Bueller Is A Figment Of Cam's Imagination

via CNBC

Perhaps Cameron is just having fever dreams on his sick day from school, about the person he wishes he was - confident, cocky, and lucky in love. This explains some of the more unbelievable elements of the movie, like the parade. Some believe that it’s Cam’s imaginary friend that allows him to become his own person by the end of the movie.

5 Fight Club Is A Messed Up Version Of Calvin And Hobbes

via IFC Center

Some fans think that Tyler and The narrator are grown up and much darker versions of the comic strip characters Calvin and Hobbs. When he is forced to let go of his imaginary friend because he’s a grown up, Calvin’s over-active imagination eventually rears its head and manifests itself as Fight Club creator Tyler Durden.

We’d like to talk about this fan theory more, but we want to obey the first rule of Fight Club.

4 Sandy Died In The Beach In Grease

via The Today Show

Even celebs can have fan theories, and this one is said to come from Sarah Michelle Gellar. She theorizes that Danny didn’t save Sandy on the beach (when they first met), and that instead she drowned. This means that the entire story plays out inside her head before she dies. In the end of the movie when she and Danny fly away into the clouds in a red corvette, that’s her going to heaven. Wow!

3 The Joker Is A Veteran With PTSD

via Inverse

In The Dark Knight, Heath Ledger’s version of The Joker casts a new shadow on the darkness from within. Some fans believe that The Joker’s fighting ability, madness, and facial scars all come from a past rooted in special ops or another highly specialized military past. The way he can handle questioning without even flinching may have to do with professional, military grade training.

2 Pulp Fiction And Reservoir Dogs Are Happening Simultaneously

via The New York Times

People wonder how Jules and Vincent manage to escape the eye of curious cops as they drive around in a blood-stained car through busy parts of town. Some say that the Reservoir Dogs bank job happens on the same day as Jules and Vincent ‘clean the car’, which also explains why there aren’t a lot of cops around, since they’re otherwise engaged dealing with additional criminal activity.

1 Groundhog Day Is About Purgatory

[caption id="attachment_481583" align="alignnone" width="1638"] via Slash Film[/caption] Much like his role in Scrooged some fans believe that Bill Murray has died in the beginning of the classic 1980s film Groundhog Day. He must live out time in purgatory until he evolves and becomes enlightened, and is able to re-enter the world, or finally move on to heaven, depending on what you believe about the afterlife.

Bella From Twilight Is Part Werewolf

[caption id="attachment_481584" align="alignnone" width="1292"] via Medium[/caption] There is a reason that Edward can’t read Bella’s mind…it’s that she’s part werewolf and capable of unintentionally short-circuiting his powers. Think about her family connection to Jacob’s family, or why she was able to procreate with a vampire, when regular humans can’t. This star-crossed lover’s story may go even further than most people believe.

Kevin McAllister Is Jigsaw

[caption id="attachment_481586" align="alignnone" width="1280"] via YouTube[/caption] Some say that Kevin McAllister was Jigsaw in training. After he was scarred because his parents left him behind twice at Christmas during his formative years, he upgrades his already fairly violent trap systems to games that involve current situations. Kevin clearly should have gone into therapy before he turned to sick, self-serving vigilante justice.

Obi-Wan Kenobi Is A Robot Clone

[caption id="attachment_481594" align="alignnone" width="1500"] via Geeky Tyrant[/caption] How else can Star Wars fans explain how Obi-Wan Kenobi does not recognize R2-D2 in a new shape after he saved his life in Episode 1. Perhaps his mind, err hard drive, got wiped. Fans of this theory think the Jedi is actually a clone called OB-1 and not a warrior, turned mentor.

Peter Pan Is An Angel Of Death

[caption id="attachment_481595" align="alignnone" width="1200"] via Vox[/caption] Some believe that Peter Pan is the agent who takes dying children to the other side, Neverland. In Neverland they don’t age (because they’re dead). The original story talks about Pan killing the Lost Boys when they get too old (because that’s against the rules). I bet you’ll never think of Pixie Dust the same way again.

The Contents Of The Briefcase In Pulp Fiction Are A Soul

[caption id="attachment_481597" align="alignnone" width="1700"] via Sick Chirps[/caption] The debate rages on for this one, but many believe this suitcase holds the soul of gangster Marsellus Wallace, who sold it to the devil himself. Satan first extracted the soul from the back of Wallace’s neck, a place where some mythology says Satan extracts your soul from. This also explains the band aid on the back of his neck and why the code for the case is 666.

Doc Brown Was Trying To End His Life In Back To The Future

[caption id="attachment_481599" align="alignnone" width="2220"] via Mental Floss[/caption] Doc Brown wasn’t exactly a successful scientist before his DeLorean went back to the future. Some suggest that his scientific failures cause him to attempt suicide by standing directly in the path of the car as he believes yet another one of his inventions is going to fail, only this time he’s wrong.

The Ghostbusters Died Crossing The Streams

[caption id="attachment_481600" align="alignnone" width="2453"] via Reddit[/caption] There were all these warnings against crossing the streams of proton packs, but when the Ghostbusters do, there is no consequence. Or is there? Some suggest they closed the door to another dimension but died doing so. But what about the sequel? Some say it’s the busters being trapped in purgatory and forced to relive another version of the same ghost related nonsense that killed them.

Willy Wonka's Chocolate Has A Secret Ingredient - Small Children

[caption id="attachment_481662" align="alignnone" width="1280"] via YouTube[/caption] Willy Wonka isn’t just eccentric, he’s a legit serial killer like Sweeney Todd, only he makes candy, not meat pies. He invites children into his factory and only one makes it through okay. In the book when a child falls into a mixer, Wonka himself says this is the secret ingredient that makes his chocolate so tasty.

Elsa & Ana Have A Long Lost Brother In Frozen, Tarzan

[caption id="attachment_481685" align="alignnone" width="2048"] via The Daily Dot[/caption] Elsa and Ana’s parents are lost at sea and presumed dead, which is the end of their story in Frozen. However some theorists speculate that the two crashed alongside an infant son, who grew up to become Tarzan. To take this theory even further, some believe this boat crash was directly related to the one in The Little Mermaid, involving Prince Eric, only he survived.

Forrest Gump's Son Doesn't Belong To Him

[caption id="attachment_481698" align="alignnone" width="1777"] via Yahoo Finance[/caption] It’s no secret that Jenny had a lot of ‘male suitors’. She also only hooked up with Forrest once, which could have been a convenient way for her to ensure that he’d raise her son should something happen to her. It would also explain why Forrest’s son was so smart, but then again Forrest’s mom was a pretty smart cookie. Either way, it’s unlikely that Forrest is ever going to get a DNA test for his kid.

It Was Harry Who Made The Dursley Family So Awful

[caption id="attachment_481712" align="alignnone" width="1200"] via The Daily Dot[/caption] In the last Harry Potter movie/book we discover Harry is a Horcrux, thus infecting those around him with an evil effect. Some say Harry being around his extended family is the reason they are such mean jerks. Ten years of exposure to a Horcrux will do that. They do seem happy to see him head to Hogwarts each year. Perhaps this is because they feel his evil presence fade away when he is gone.

Sid Redeems Himself In Toy Story 3 As A Garbage Man

[caption id="attachment_481729" align="alignnone" width="1280"] via Film School Rejects[/caption] Once Sid is scared by toys who come to life in Toy Story, he changes his evil toy destroying ways. As a grown up he becomes a Garbage Man who has a specialty for finding, saving, and fixing broken toys. In Toy Story 3 we see a Garbage Man with a skull shirt, just like Sid’s, and similar mannerisms. Could it be the same person all grown up?

Nemo Only Exists As A Way For His Dad To Cope With His Death

[caption id="attachment_481732" align="alignnone" width="1536"] via Romper[/caption] Some believe that Finding Nemo is all in Marlin’s head as he copes with the grief surrounding the death of his wife and children. The name Nemo really means ‘no one’ in Latin, lending validity to this theory. We see Marlin go from all the classic stages of grief from anger (over Nemo being careless and unsafe) to acceptance when he is willing to let Nemo go. Although this theory makes you wonder why there is a sequel if it’s about the end of grief. Sources: Shortlist, Looper, E Online, Clipd, Games Radar,