>>I tend to read a book once and then I am done with it
This may be true for novels, but science, engineering and math books are usually used for a long, long time. I still have all of mine for reference and every once in a while I do come back to many of them.
I used to do that a lot with my math books and computer science books (I have a degree in math and work as a programmer), but I eventually found that while I prefer to use a book to learn new material, I virtually always use the Internet for a quick reference and only rarely refer back to them.
This may be true for novels, but science, engineering and math books are usually used for a long, long time. I still have all of mine for reference and every once in a while I do come back to many of them.