Nobody is going to know everything. No matter who you are and how hard you've studied, there will be a ton of information you just don't have the time to take in. Even our best universities don't contain the full breadth of history and shared knowledge. The people we praise as learned and scholarly only truly know a fragment of what there is to know.

If you're a horror movie fan, chances are one of the topics you've been tasked with knowing is continuity. As franchises progress, it gets harder and harder to keep track of what's going on. That comes down to loads of different factors. Typically, fans just care more for their beloved series than the powers-that-be who are making them. Halloween, for instance, is fraught with glaring continuity problems. The saga of Michael Myers, as explored in the first two Halloween movies, is abandoned in the third. Then it's resumed in the fourth, carried through to the 7th, which then recons the previous three. After another movie, it's rebooted. Then there's a sequel before it's rebooted again with a trilogy of "re-quels" that picks up the story from the first movie and ignores the nine movies in between.

This isn't a phenomenon that's unique to Halloween, either. Next time you see your friend who's obsessed with horror, ask them about Hellraiser continuity, and watch as smoke billows out of their ears.

It should be no surprise, then, that even the actors in some of these movies struggle to keep up. It's not their fault.  Take, for instance, Candy Clarke from Amityville 3-D. Despite praising the actors she shared the screen with, Clarke was unaware when reporter Bobbie Wygant asked her about 3-D following in the footsteps of the first two Amityville movies.

"They're making a point," said Wygant, "to let people know that this Amityville has nothing to do with the other two." She then asked actress Candy Clarke why that was.

"I have no idea," said Clarke. "Are they really making a point about that? Some totally different people have moved into the house. Maybe that's what they mean. And different things happen to them. And another different thing about the film is that it's shot in 3-D, and, so, hopefully, it'll look totally different."