I don't care how fat most books are since it's the first 25 or so pages that determine whether or not I'll read more of it. I've liked most books I've finished, and several of them were interesting enough that I've read them more than once, and referenced them a lot of times.
It's a little sad, at times, for a book to end. What doesn't end, though, is that when a book engages my mind, I bring as much to the book as I get from it.
My kids bought me an 8" tablet for Christmas, and stored a little over 800 books, fiction and non-fiction, in it. All the books are best sellers, and a little over 300 are science fiction. They also stored about 2000 songs, (lyrics, tabs, sheet music) plus audio and video, for my ukulele.