Something that totally shocked you learning it or realizing it. I might be using the wrong wording here, but ill give you my example:
In Ocarina of Time, we all know the Triforce was cut, or otherwise not something you get in the game, save for in the cutscenes towards the end. BUT - did you know you can actually go find it and see it in the game?
If you have a Gameshark, turn on the levitation code. Go go Zeldas Cortyard in the room where she is, and fly over the wall. When you fall, you’ll land in a pool of invisible water, and underneath the center of the room with the flowers, look down - there it is. Can’t interact with it, but you can see it, and i choose to believe putting it in that exact spot was intentional for lore reasons.
What do you got?
The TES stuff is my jam. As much as I don’t really care for Bethesda now, I appreciate that even up through Skyrim, a lot of the wilder lore tidbits are acknowledged and hinted at, just never put at the forefront. The Empire having asteroid colonies and spaceships, Dwemer steam trains, genocidal time traveling cyborgs in Oblivion, etc.
Love the sub canon about what the eye of Magnus actually is. It’s so, so dumb I can’t help but like it.