The answer with no question.

[Qwertystop]

I really like that idea, Anxe/Cespenar. Not so much a magical sight, and more that, by the time you know that much, you can reasonably get asked any question and, with a little though, be able to use what you know to predict the answer.

So for law, if there's a huge tome of regulations you've never read for a country you've never visited, you could pretty much state any minor detail or loophole just by comparing the style to the vast breadth of other systems you've seen and making an informed guess. Or for geography - even if you've been dumped on another unknown planet, you could look around and predict where to find any geological features, just by taking in the subtle environmental features and working out the pattern.
Still, I guess it's up to the DM, as houserules could make this anything from worthless to broken.

This, definitely.