Telling Story Canon From Personal Bias, Erroneous Memories, & Fanwank
Trying to sort out what's canon and what isn't can be tricky work sometimes. Even when we think we know what really happened in a story, our own minds may have fooled us somehow, leading us to firmly believe things about the work or its characters that just ain't so. While we will never be entirely free from making these errors, we can reduce the odds that we won't commit them as often by being aware of them and taking reasonable precautions against them.
How we can fool ourselves into believing things that aren't so.
These are four very common ways our subconscious minds fool us into believing things that aren't necessarily true:
Fabricated & conflated memories: Whenever there are gaps in our knowledge, our subconscious minds will try to fill in the blanks with whatever seems to make sense and patch the holes together in whatever way seems the most coherent. Thus our minds can trick us into believing that something that never actually happened took place, or we might confuse and conflate disparate events or objects. For example, some casual viewers of the Marvel films mistook the Tesseract for the Casket of Ancient Winters because they mainly remembered that they were both blue, both boxy, and that Loki had both. They didn't remember that they were different sizes, that one was a rectangle while the other was a cube, and that one of them had been in the possession of the frost giants on Jotunheim while the other had been hidden away on Earth.
Interpolation: When all of the details surrounding something aren't immediately clear or when we don't remember them perfectly, our minds will try to fill in the blanks with what we already know about similar things. For example, many people who watched Thor picked up on the superficially-Medieval appearance of the characters and places of Asgard and assumed that Asgardians were therefore essentially a pseudo-Medieval people who would be utterly baffled by things like microwaves and televisions, forgetting that the Asgardians were actually advanced enough to build what basically amounted to a stargate.
People also frequently interpolate characters' personalities and motivations, subconsciously filling in unknown areas with the personalities and motivations of characters they perceive to be similar, or even with their own. Problems arise when they fail to critically compare what they think the characters' personalities and motivations are compared to what the source materials actually show them to be.
Imposed preconceptions: Sometimes, what we're told happens in a story can color the way we see it so strongly that we miss or misinterpret what actually does happen. For example, some fans of the Pretty Soldier Sailor Moon manga believe that the phantom silver crystal had been passed down from Sailor Moon to Sailor Chibi Moon whereupon it turned into the pink moon crystal, but a more careful look at the manga shows that the phantom silver crystal and the pink moon crystal are two separate objects entirely. Even I fell prey to the misconception despite having read that part of the manga several times - it wasn't until someone else pointed it out that I realized how off I'd been.
This can also happen (and very often does) with adaptational works, where people are so accustomed to the older version of the work that they simply assume that the settings and characters work in the same way as they did the old one, rather than critically examining whether they actually do and taking the new work on its own terms and merits.
Observational bias: When we get an idea or belief about something that we want to be true, we tend to remember facts and details that support that idea or belief while forgetting or downplaying the ones that dispute it. For example, fans of villains who are desperate to believe that said villains aren't really bad will often glom onto any perceived positive traits of the villains while ignoring the negative ones. People who want to believe that a protagonist is really a horrible person will frequently do the inverse by picking out the character's flaws and misdeeds while ignoring the positive traits.
How we can avoid fooling ourselves.
Never be too sure of what happened in something until you've seen it at least three times. The reason is that when you watch something you're certainly not going to remember all of the details correctly the first time, and there will inevitably be important details you'll miss. The second time around you'll remember and notice more, but there's still probably plenty that you're missing. By the third go-round, you should have a fairly decent idea of what happened. And of course, with each repeated viewing, your memory of the work will become more complete and more accurate.
Question the fundamentals. Question the most basic assumptions you make about a setting or character, or that other people believe about a setting or character and insist are true, and hold them up to scrutiny. Does the magical macguffin really do all people believe it does, or are they jumping to conclusions based on spurious evidence? Does a character really exhibit the traits that so many people play or write xir as having, or were they made up from whole cloth, or drawn from a similar character, or from another character played by the same actor? Does a character really show signs of possibly being a better person than xe usually lets on, or are people just grasping for straws? Or is a character people believe to be good and respectable actually a complete jackass who only gets through challenges because xe gets lucky? You'll find that a lot of the things people commonly believe about a story and/or its characters completely fall apart upon critical examination.
Don't trust what the characters say too much. Too many times, people just take the characters' words at face value and don't bother to compare them against what what's actually shown. Yes, Jeff might say that Sadie is nothing but an airheaded ditz, but does the evidence actually point to Sadie being nothing but an airheaded ditz, or do Sadie's actions and accomplishments say otherwise?
Remember, you cannot prove a negative. A lack of evidence against your belief is not enough to conclude that your belief must be true or considered as a serious possibility. There must also be positive evidence for your belief: if you believe a character to be an alcoholic, then you should be able to point to instances that positively indicate alcoholism - ie, needing a drink just to function, rather than occasionally getting drunk at parties or with friends.
Try the scientific method. Outline the things you suspect or believe about a story or character, then think out what kinds of things could happen in the story to prove your belief false. For example, let's say that you believe a character is really an android passed off as a human. At this point you'd stop and ask yourself what would qualify as evidence that the character is not an android - for example, bleeding red blood when injured and receiving medical treatment in a hospital would be pretty strong evidence against this hypothesis. Then, you'd sit yourself down and keep your eyes open for any of your falsifying criteria, or for anything else that strongly suggests that your hypothesis is wrong. When you're done, examine the weight of the evidence and where it all really points: a character who bleeds just a little might still be an android (the android's creator might have equipped the android with fake blood in case of an emergency), but a character who bleeds, requires a blood transfusion from someone who is definitely human, and needs surgical stitches almost certainly isn't an android.
Long story short: Don't trust your own memory too much, question your assumptions, and make careful observations to work out what's canon and what isn't.
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