The experience of reading a book with someone else — not simultaneously but in relay, each reading the same copy and sometimes leaving notes for the other — is something I recommend to any two readers who are close. The marginalia becomes a conversation, the shared object becomes a shared experience.

I've done this with one other person for ten years. We've read perhaps thirty books this way. The copy of Gilead we read together has three colors of ink in the margins — mine, hers, and a second pass from each of us responding to what the other marked. It is a record of a reading relationship that neither of us could have had alone.

The book in this case becomes something that belongs to both of you. The annotations are part of the text in a way that solo annotation isn't, because they're addressed to someone specific.