Why are some long novels so much harder to read than others?

I think I might read The Count of Monte Cristo*. I don't know. It is still up in the air. I am seriously considering it however. The book looks pretty interesting, and I've had numerous people recommend it to me. One of my students at Johns Hopkins even said it was his favorite book! Now that is a recommendation.

The downside is that it is long. Like, Ga…