I hated having to read (fiction) books for class. I had to go at the class speed, not mine, and sometimes had to analyze books to the point of not enjoying them anymore. If I feel like "settling" for enjoying a rip-roaring good story instead of looking for the fifth level of meaning, that's I want to do.
My favorite example is
The Hobbit, which we had in one of my middle school classes. By that time, I had probably read it maybe five times on my own, as well as all three Lord of the Rings books, but I ended up flunking one quiz on it because I had no idea what had happened in Chapter X, as opposed to Chapter X-1, or X+1, or X+2, since I knew the book so well that I didn't read it by chapters. So my answer described what happened partly in Chapter X and partly in some other chapters, and the teacher felt that meant I hadn't been "taking my assignments seriously".
For me, at least, assigning books tended to ruin them for me...at least temporarily.
I still love Tolkien's books, BTW, but it took a little while to recover from having
The Hobbit in class

.