Following the previous post, and Oreneta's comment, it is interesting to ponder why one chooses the next book to read.
There are sometimes limitations about what is available. On holiday and at airports you pick up and read books you would never normally associate with. Occasionally they are gems, but mostly they are just passing the time. I have an obvious advantage because I work in a public library, and I buy the books, so if there is something I want to read I will usually be able to get it from stock, or buy it for the library and read it first.
Sometimes you select a book because it has come recommended, though you need to have a good idea about what other people like to read because reading tastes are so individual. You may know that a book could be a good book, but it isn't a book which will particularly appeal to you.
I am going to start reading books for the Dagger in the Library award from the Crime Writers Association soon, so I will be reading crime books suggested by lots of other people. Some of them I will enjoy and some I will hate, and some will be just dull.
Sometimes though you find a new author and it is like being given a prize. Here is a person who writes books that you absolutely love, and he/she has written lots of others that you have yet to read. It solves the reading dilemma for weeks if not months. How lovely!
Or you develop an interest in a subject and start reading round that topic - for me recently it has been the Russian Revolution, and there are lots of good books on that topic.
I used to review science fiction books for sf magazines which was interesting because you never knew what would come through the door. Some were good and some were awful, but because I was writing a review I had to finish it and analyse why I liked/disliked it, what was good/bad about it, whether it did/didn't achieve its objectives. If I am reading a book for pleasure then if I don't like it, or am not enjoying it, I won't finish it. Why waste time on a book I am not enjoying when there are so many out there that I would enjoy?
I don't know what I would do without books. I always have at least 1 on the go, and never travel without them. I love their generosity, the way they give me so much, open so many doors, give me information, tell me stories, make me laugh or cry, make me think or change my mood.
I think I am a bit of a bibliophile.