" You know, old books are a big problem for us. Old knowledge in general. We call it OK. Old knowledge, OK. Did you know that ninety-five percent of the internet was only created in the last five years? But we know that when it comes to all human knowledge, the ratio is just the opposite - in fact, OK accounts for most things that people know, and have ever known. "

― Robin Sloan , Mr. Penumbra's 24-Hour Bookstore (Mr. Penumbra's 24-Hour Bookstore, #1)