Some books are easier to read than others, but that doesn't mean they are the ones you most enjoy. Sometimes you read slow to savour it better.

I think it's always a good idea to read a few books in parallel, a chapter or so from one and then from the others in turn. That way the easy ones pull you though the harder ones, and if you pick them right the different qualities of the books echo one to another.

One interesting thing is to come back to a book you thought you'd read, and find that you were just racing through it for the story or whatever, and missing out whole aspects of it. As if you had listened to a song just for the words and hadn't noticed the tune, or listened to a tune for the melody, and missed what the instruments were doing.