This is the enormous gasp, not of someone who is offended, but of someone who is really excited to get to explain her favorite thing.
"Books are the most useful thing humans have ever invented!! It is like, so, you know how if you want to learn a thing and don't know how you basically have to wait patiently while somebody else decides when they have time to tell you the thing, and even when you like the person it's sort of inconvenient and horrible? If they instead put all the words they would have said on paper, and bind up the paper into a nice sturdy organized pile, then if you have a copy of the book you can have all those words whenever you want."