Charlie tells us about how he and Bill talk about life together: Charlie tells Bill about his psychiatrist, and Bill talks about where he went to school.
Bill even lets Charlie smoke in his office, but he gives him a pamphlet on the benefits of quitting.
Now that Charlie's done with On the Road, he gets a new book: Naked Lunch by William S. Burroughs. It's not about a restaurant violating health codes; it's about a junkie.
Either Charlie told Bill more than he led us to believe, or Bill is quite insightful into Charlie's personal life and his recent drug usage.
At home, Charlie tries to read Naked Lunch but it just confuses him.