This made me think of Umberto Eco’s Foucault’s Pendulum, where you find yourself thinking “I need to look some of this stuff up, it’s becoming hard to know if I understand it all”, but that is part of the satirical commentary he wanted to make - it’s very meta, very good, not knowing all of the esoteric references is the exact point.
Foucault’s is amazing. It’s a great story, but it also delivers a visceral experience that really mirrors what the characters are feeling. One of the best “medium is the message” books.
I think that property is essential to really good books. The running of Aragorn and Legolas and Gimli is a long boring slogto read. The trek up Mt Doom is agonizing.
The transformation of writing from the awesome kids tale of Sorcerer's Stone thru the awkwardly adolescent middle books to the powerfully adult writing and plots of Deathly Hallows is such a effective parallel to the kids growing up.
