Proust's multi-volume novel Remembrance of Things Past gives us every little detail of the life and times of its protagonist, the narrator. Like, every detail. He eats a pastry and it takes multiple hundreds of pages. Sure, it's 'cause it makes him reflect on his whole life up to that point, but still. A pastry.
Proust's style is really dense, and he layers image upon image upon image until the whole book becomes a close reader's dream. No wonder de Man loved it so much: the book's language is richer than a triple chocolate fudge brownie sundae, with ambiguity sprinkles and a juicy red paradox on top.
de Man's Allegories of Reading opens with an interpretation of one of Proust's particularly gooey passages, and de Man later returns to the same part to deconstruct it some more. His readings set the stage for deconstructive and poststructuralist readings of literature—not that he didn't care about philosophy, too.