If the laws of reality are simulated, then they must be computable. A giant switch statement isn't going to let you figure out how to make time travel consistent. They couldn't easily check every possibility and see if it's consistent. Even if they did, that would mean they're simulating all of them, including the inconsistent ones, and there'd be no reason for Harry to find himself in a consistent one.

Didn't Harry already point out that the time travel was not computable, and as a result it couldn't be a simulation? Although he didn't go to great lengths to prove that. He assumed that there was no force subtly manipulating events to make sure time travel is consistent. In fact, he is in a simulation run on the computer that is Eliezer's brain.

And the entire HPMOR fanbase has just now googled the concept. Promotion of ideas is what HPMOR's purpose is, after all.

Prediction: Atlantis wasn't a catastrophe that the Mirror was too late to avert. Rather, the Mirror was completed, and the Atlanteans removed themselves to a realm of existence within the Mirror. Confidence: 5%.

I see. "Heart's desire" indeed.

So... Atlantis managed a neutral AI? But see convergence of methods - I'd expect a hypothetical NAI to be considerably harder to build than an FAI.

(Also, nice Duane shout-out.) In what sense is Altantean Magic more like Wizardry than post-Antlantean magic, though? Just the bits about making the Holy Grail as opposed to merely operating it?

(Heh. True Magic.)

Even Riddle would wish to be happy, I think. Or rather, if he knew more, was more capable, and was more the sort of person he wants to be... he would wish to be happy and immortal. Why not, after all?

I wonder how Dumbledore turned that into a trap, though?

For that matter, if Harry is right and Aberforth has the stone... there is another way of getting it, if this one is copy. There's more than one way to see someone who's dead, after all.

Can the mirror be used to hack the Time Turner restriction? GAH!

Also, reading the letter backwards:

Is how not your face but your coherent extrapolated volition .

"There's something that would make you happier than that," Harry said, his voice breaking again. "There has to be."

Muggle research in the 2010s has revealed much about what actually makes people happy, and how often people are deceived. The best way to find out is with one of those mood-tracking cell phone apps, which eliminate the biases of memory. Quirrell doesn't have that, but as an approximation, I searched the PDF for the word "smile", which appears 310 times in chapters 1-106, and the word "enjoy", which appears 32 times. What did I find?

“Do you know,” the Defense Professor said in soft reflective tones, “there are those who have tried to soften my darker moods, and those who have indeed participated in brightening my day, but you are the first person ever to succeed in doing it deliberately?”

Interacting with Harry makes Quirrell happy. Moreso than killing idiots. Moreso than teaching Battle Magic. Killing him would be a grave mistake.

Quirrell will be killed by Harry at the end -- but this is all a part of the plan.

Suppose that Quirrell is not the original Riddle, but is just another Riddle's copy. If Quirrell and Harry are both copies of the original Riddle, the original Riddle had no reason to prefer Quirrell's life to Harry's life.

The story about a good hero saving the world by defeating a horrible villain: he did not have to fake it. He could make it real, by letting two of his own copies fight against each other. Realistic hero Harry will be better than a fake hero; he will be more authentic; there will be no risk of discovering his secret in the future.

Just like Harry had a magically induced blind spot in his mind, also Quirrell can be manipulated. (Memory changes, imperius, unbreakable oath... there are many options.) This is why Quirrell does not kill Harry, why he teaches him things, any why he is making him angry at the end. This all is Quirrell's purpose; he is just a tool to prepare Harry for the role of king of the world. Quirrell is not optimizing for Quirrell; he is optimizing for Riddle.

So, this is what I imagine: First Riddle created his copy, Quirrell. Maybe with a specific purpose, maybe just as a backup copy. But later he was not satisfied with the outcome, when he realized that his new memories will not be preserved. So he later created another copy, Harry, killing himself in the process. Before that, he somehow magically commanded Quirrell to train Harry for the role of the king.

Quirrell may not be aware of this, because he was magically brainwashed. This is the power he knows not, the power that will cost him his life at the end. He is actually magically forbidden from killing Harry.

Not sure if the original Riddle was a sociopath (that would explain why he doesn't mind his two copies fighting to death against each other), or whether Quirrell's personality is another effect of the magic, preparing him to be the perfect villain.

Anyway, when Harry outsmarts and kills Quirrell at the end... this is exactly what Riddle has planned from the beginning. This was his plan for becoming a hero. (Maybe there will be a moment when the victorious Harry/Riddle will regain all original Riddle's memories. Or maybe not, because that could make him behave less authentically afterwards. Or maybe yes, because discovering that your favorite teacher was actually Lord Voldemort and defeating him is the most appropriate moment for a minor personality change.)

EDIT: Oh, now it's obvious what is in the mirror, any why Harry has to be there. The mirror contains Riddle's memories that are to be implanted in Harry soon. By the way, Dumbledore already knows many of these things, and has his own plans.

If you find it boring it's probably not for you. I enjoy the language, the descriptions and so on. It's the same as my recommendation for LOTR. I liked it a lot but I don't think everyone should. I find both pleasant to read even when nothing is really happening in the story.

It's a reference to the Gormenghast trilogy, of which one of the main characters is an isolated teenager named Steerpike.