I think many people are intimidated by long books. What if I don't like it? I'll have wasted all that reading time! My brain will be full. I can't possibly read something else at the same time.
You see? Not a big deal. If big books intimidate you, my suggestion is to just hack at it 100 pages at a time. Then read a quickie. Then go back. Honestly, if you don't like a book by the time you've reached midway, your best off to skip to the end, and then quit.