I do experience the same phenomenon where I feel other people haven't actually read books. The book I've experienced this with the most is Infinite Jest. It's twofold in that people both misunderstand basic pieces of the story ("what ethnicity is Hal (arguably the book's protagonist)?" is a common mechanism by which I determine people didn't read or didn't understand the novel), and that I've never ever once online or in person seen commentary about the central "thing" the book is doing, although it's blisteringly glaringly obvious and I'm afraid everyone else just knows it and it's too obvious to state rather than being something only I noticed.
So... Anyone ever actually read IJ?