It's a common fact that the FNAF storyline is something debated about. The more answers given, the more questions asked.It's the same concept as being afraid of the dark. It's not the thing itself that we're afraid of, but the unknown. Humans are afraid of that which they don't know, something that could overpower them in the end. It is for this reason that we will stop at nothing to know everything, no matter the consequences.If we don't know everything, then there's always the chance that the one thing, that one puzzle piece left out, can change everything you thought you knew. For example,let's use something we found out from the most recent installment in the series, "sister location". It was given to us that it was not in fact "dave or "vincent" that was stuck in the springtrap suit, but rather michael, his son.This one simple fact changed something that almost everyone in the fandom had already classified as hard fact. Now, because of this, people are left with more unanswered questions than we believed we would have. Now, instead of giving what I believe to be the storyline, i'll give what a curious subset of you want, why the storyline is considered such a mystery. Yes, it is true that we had already figured out that dave/vincent had two sons, and that people believe it was the younger son that fell victim to the bite of "1987", and that it was the older of the two who played a significant role in this bite. Then, once they figured out dave/vincent wasn't the one in the suit people assumed that "michael" was the older son and that the spirits chased him into the suit because the victim of the bite blamed him. But then, there's a smaller percentage (extremely smaller) of you people out there that believe that "michael" is the younger brother (how that works I have yet to figure out). That is the reason we are afraid of the lore. All these people rage-debating gives you a sense of insecurity about yourself, like the world is against you and that you have to join the majority or you'll crack under the pressure of being constantly attacked because of your views on a game. However, you're afraid that by joining the majority you'll be lulled into a fake sense of security and be broken by an unexpected force. And it's true. I have learned over the years that people can be so set in their opinions that they'll do anything to someone who thinks differently. That is one of the reasons why FNAF is a horror game.