I would agree about "most" of the history and trivia, but not "all". Given his behavior in Chapter 40, it at least seems likely that he did not know as much as Harry about the Hallows at that time. This is understandable, as Harry has a Hallow and therefore cares more than the Defense Professor, who doesn't have one and doesn't have a particular reason to search for any of them. He wouldn't decline a chance to try the Stone, but he doesn't have much reason to believe it works as advertised and therefore didn't plan to seek it out. Now that he remembers "a peculiar ring [he] saw on the finger of a man [he] met only once" (Chapter 26), he is much more interested and probably knows more publicly-speculated information about the Hallows than Harry even if he doesn't know some of the specifics Harry learned in TSPE.
Similarly, the Defense Professor doesn't seem to care about whether other beings are sentient, so he probably does not know as much about the fairy tale of the tale of the Lady of the Flying Squirrels (Chapter 49), even now that Harry has mentioned it.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 96. The previous thread is at almost 300 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, .
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: