I recognize what you're talking about, from mathematics. But you're either being genuinely interested, in which case it's a delightful slog that you're keen on, or else (more commonly) you're being perversely stubborn for external reasons like prestige. In the latter case it's a sort of perverse-learning that isn't really worthy of the name, and although it's somewhat more sophisticated than rote memorization, the understanding is shallow and short-lived. I used to hate mathematics, so I did six years of pure mathematics, and now I really hate it.
I was reading parts of the Iliad for fun recently, on the other hand, because somebody had asked a question, and I enjoy slogging through dense texts to find obscure facts. It's horribly written because names are frequently oblique, like "the old one" or "son of ..." instead of an actual name, and everybody talks in flowery speeches. Shakespeare suffers from the flowery speeches thing too. Beowulf is also tedious to read because of all the kennings (talking in riddles). Chaucer on the other hand is sometimes dirty and amusing. Tolstoy, never tried. Gilgamesh, though, is well-written, fast-paced and highly entertaining, I reckon literature should probably have stopped there, all the authors after that were just derivative hacks.
But in summary it depends what you're into.