We all have those theories we believe, even though we know they're probably not real. Ghosts, aliens, zombies, whatever it is...you've got one.
Celebrities are no different when it comes to conspiracy theories. Even the famous let their minds play tricks on them.
1. Woody Harrelson
Harrelson is considered one of the most informed people in Hollywood, known for his connections to some pretty important people. This is why his theories are often believed to be based in fact. Harrelson is a 9/11 Truther, a JFK assassination denier, and believes in secret societies bent on creating elitist rule (such as the Illuminati.)
2. Demi Lovato
The singer and former Disney star has always been outspoken about what she believes in, whether that's being sober, supporting equal rights, or being true to yourself. She's also somewhat of a self-proclaimed expert on the existence of aliens.
"I know they exist," she said in the past. Exactly how she knows this has yet to be seen, but I'd love to know her sources. Let us in on the secret, Demi!
3. Jesse Ventura
The former actor, wrestler, and US Navy member has a slew of conspiracies he believes in. He even has a TV show about them all called Conspiracy Theory. He also believes 9/11 was an inside job. Ventura also maintains that the government uses mind control on its citizens and that Area 51 is a big cover-up for alien life forms. Ventura says he's been questioned by "unidentified individuals" before, which is why he believes in these theories.
4. Jenny McCarthy
McCarthy has been extremely outspoken about her belief that vaccinations can cause autism. McCarthy's own son has development disabilities and she believes they were caused by vaccines. McCarthy claims it's all part of a multi-billion dollar industry aimed at getting more money out of American citizens.
5. Randy Quaid
The ever-in-trouble Randy Quaid believed he was being followed by hit men that were out to get him. There's a whole group of people that believe celebrities are killed in a specific order, and it sounds like Randy is one of them. He also believes Heath Ledger was murdered, despite the coroner confirming it was an accidental overdose.
6. Marion Cotillard
The actress believes in one of the most common conspiracies in the world: that the moon landing was fake.
"Did a man really walk on the moon? I saw plenty of documentaries on it, and I really wondered. And in any case I don't believe all they tell me, that's for sure."
Cotillard also believes 9/11 was a complete hoax. She believed it was a ploy by the building owners who didn't want to spend the money to remodel the outdated buildings.
"We see other towers of the same kind being hit by planes, are they burned? There was a tower, I believe it was in Spain, which burned for 24 hours. It never collapsed. None of these towers collapsed. And there [New York], in a few minutes, the whole thing collapsed."
7. Bruce Willis
The Die Hard actor doesn't believe Lee Harvey Oswald assassinated John F. Kennedy...at least not alone.
"They still haven't caught the guy that killed Kennedy. I'll get killed for saying this, but I'm pretty sure those guys are still in power, in some form. The entire government of the United States was co-opted."
8. Mark Ruffalo
Though he doesn't deny it's severity, Mark Ruffalo doesn't buy the official story about 9/11.
"I'm baffled by the way all three buildings came down. My first reaction was that buildings don't fall down like that. I've done quite a bit of my own research ...The fact that the 9/11 investigation went from the moment the planes hit to the moment the buildings fell, and nothing before or after, I think, makes that investigation completely illegitimate. If you're going to do a criminal investigation, you have to find a motive. We didn't follow that. It was quickly pushed away, obviously. There was no evidence at the biggest crime scene. None of us know what happened but I'm totally and completely behind reopening that investigation. Where is the money? Follow the money, guys!"
9. Kylie Jenner
The youngest Kar-Jenner believes in chemtrails, though it's not clear she knows what they are. Kylie posted a tweet about the theory, in which many people believe the American public is being poisoned and that the government is controlling weather patterns. Kylie hasn't confirmed what she actually believes is happening, just that she doesn't like it.
10. Kanye West
The rapper has many theories he believes in, including the Illuminati, but the most outrageous one is that HIV/AIDS was developed by the CIA. That's right. Kanye, among others, believes the government created the virus synthetically and placed it in Africa as a testing ground for biological warfare. He says it's similar to how the CIA and FBI allowed crack into black communities in the United States as a way to break up gangs and rebel groups.