In this article, I examine the communicative practice of mentioning a personal experience as a vehicle for challenging a peer’s perspective. I study this in the context of therapeutic community (TC) group meetings for clients recovering from drug misuse. Using conversation analysis, I demonstrate that TC clients use this practice, which I call an I-challenge, to influence how their peers make sense of their own experiences and to do so without commenting on those peers’ experiences and perspectives. This study highlights the power of talking in the first person as a means of influencing others—a notion previously made popular by Thomas Gordon’s work on “I-messages.” Additionally, this study illustrates a novel way of studying social influence. Whereas previous research in social psychology has focused on the cognitive constraints behind phenomena of social influence and persuasion, here I contribute to understandings of the interactional norms underlying the organization of influence as a structured and coordinated domain of social action.