I had a teacher who had us read a certain amount of books on our own per semester. We could choose pretty much any book.
I chose a book in the Hitchhikers Guide To The Galaxy series.
He would check that we’d actually read the book by sitting down with us and turning to a random page, reading a bit and then asking us what was happening, who the character he’d read about was, that kind of thing.
Well, yeah if you’ve ever read HHGTTG books, you know it can go on random tangents. My teacher read one of these random tangents about a character never seen before or again, and which had no connection to the rest of the story at all except as a setup to talk about something else that did have to do with the story.
My teacher could not wrap his head around this. He read a couple more random selections and I did explain those, but his assessment was that I had only hastily skimmed the book instead of properly reading it, and therefore lowered my score on what was normally an easy 100% assignment.