Comment by bryanrasmussen

your friend would be a possible infection point (not a virus) for the memes encoded in the book. As a form of memetic transmission a book, if read all the way through, is especially potent - take Ayn Rand Atlas Shrugged as an example. Books are many memes assembled together into a stable culture that reinforces the memes. The virtues of selfishness as a meme would be weak and probably die pretty quickly without all the support the book offers.

Friends probably are not wide spreading infection points, the way reviews in professional journals are or the idea that successful people have recommended things, but they are especially successful at making the transmitted meme stick, as you will keep getting reinfected from them over time. Unless you break up that dangerous friendship!!