Wake me when it's over: Unreadable literary classics

Are there unreadable literary classics? Yes, of course. I doubt that anyone has read Finnegans Wake start to finish outside of a graduate seminar. Has anyone read the complete Canterbury Tales? Even the Parson's? Has anyone read Paradise Lost straight through? And more recently, I guess Infinite Jest is a cult classic but who's actually read it? And what about Gravity's Rainbow from a generation or two back - everyone started it, at least I did. I was blown away by its scope and grandeur of design, but ultimately felt that, to understand it at all, I would have to give it far more attention and devotion than it was worth - or than I could manage. These are some of the obvious ones - and some other classics of great magnitude I would say may be challenging but are totally readable: Magic Mountain, Ulysses, In Search of Lost Time, War and Peace, and Moby-Dick, to name just a few. Adding another to the unreadable classics: Robert Musil's "A Man without Qualities." I started it several years ago, when the beautiful 2-volume Vintage pb came out, and read about 400 pages (out of about 1,500), and just grew totally weary. Yes, the thoughts are weird and profound, a portrait of 1920s (?) Austria, told with surreal humor and with the odd precision of a dream in which nothing quite matches up. Many long descriptions of the attempt to celebrate the state of Kakania through the Parallel Campaign honoring the emporer, and the rise to power of the title character, Ulrich - but through the hundreds and hundreds of pages there is no plot whatever and you're just sucked into the vortex of Musil's strange view of the world. Tried reading again recently and just could not get my way through it - a monumental work that is entirely off-putting.