The answer to this question should address the context within which Bill offers this idea to Charlie - the moment when Charlie s sister is hit by her boyfriend. However, an effective answer should also focus on Bill s concern over Charlie s observational tendencies. Charlie is constantly thinking about how other people experience love, and Bill tries to provide a framework that will help Charlie to work through his own relationships. Charlie uses this quote to talk to his sister and also to handle his erotic and romantic feelings for Sam.
The friend in Charlie s letters goes unnamed throughout the novel. Because of the friend s anonymity, the reader of the novel can feel an intimacy with Charlie. By the end of the novel, the reader feels as though Charlie has been writing to him or her in all of the letters.