There were mysterious questions, but a mysterious answer was a contradiction in terms.

You couldn't changed history. But you could get it right to start with. Do something differently the FIRST time around. This whole business with seeking Slytherin's secrets... seemed an awful lot like the sort of thing where, years later, you would look back and say, 'And THAT was where it all started to go wrong.' And he would wish desperately for the ability to fall back through time and make a different choice. Wish granted. Now what?

Between hindsight bias, fake causality, positive bias, anchoring/priming, et cetera et cetera, and above all the dreaded confirmation bias, once an idea gets into your head, it's probably going to stay there.

If you want to build a recursively self-improving AI, have it go through a billion sequential self-modifications, become vastly smarter than you, and not die, you've got to work to a pretty precise standard.

Have I ever remarked on how completely ridiculous it is to ask high school students to decide what they want to do with the rest of their lives and give them nearly no support in doing so? Support like, say, spending a day apiece watching twenty different jobs and then another week at their top three choices, with salary charts and projections and probabilities of graduating that subject given their test scores? The more so considering this is a central allocation question for the entire economy?

Physiologically adult humans are not meant to spend an additional 10 years in a school system; their brains map that onto "I have been assigned low tribal status". And so, of course, they plot rebellion - accuse the existing tribal overlords of corruption plot, perhaps to split off their own little tribe in the savanna, not realizing that this is impossible in the Modern World.

Many have stood their ground and faced the darkness when it comes for them. Fewer come for the darkness and force it to face them.