Laurence Sterne, for example, intersperses the text of Tristram Shandy with blank pages. Samuel Beckett's Watt drags on interminably with redundant sentences. Most people die without getting through all (or even any) of the volumes of Marcel Proust's Remembrance of Time Past.
But no author, I believe, has ever posed a greater challenge to the reader than René Descartes. I do not refer to his extremely long sentences with extended use of subordinate clauses. I am talking about his demand, in Discourse 5 of Discourse on the Method of Properly Conducting One's Reason and of Seeking the Truth in the Sciences, that readers do the following prior to perusing his description of the circulation of blood:
I would like those who are not versed in anatomy to take the trouble, before reading [further], to have cut open in front of them the heart of some large animal which has lungs, because it is, in all of them, similar enough to that of man, and to be shown its two ventricles or cavities.(p. 66.)
The only other creator, in my awareness, who requires his audience to sacrifice animals in conjunction with the partaking of his words is God.
Then again, the man who wrote, "I have hardly ever encountered any critic of my opinions who did not seem either less exacting or less equitable than myself," has never, to my knowledge, been accused of modesty.
(Image of dissected cow heart from University of Utah site)