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 pr

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.