Idiomatic formulations are often successful in achieving affiliative responses: They are hard to challenge both because their generality makes them independent of the specific details of any particular person or situation, and because they invoke and constitute the taken-for-granted knowledge shared by all competent members of the culture (Drew & Holt, 1988). Drawing on data in which women with breast cancer talk in groups about their experiences, in this article we explore how they resist the rhetorical power of the idiom "think positive." Three resistance strategies are described and illustrated: (a) pauses and token agreements, (b) the production of competing idioms, and (c) particularization. The article ends with a brief discussion of the implications of these findings for conversation analysis and for current debates about the value of fine-grained conversation-analytic approaches within discourse analysis. Think positive: think in a confident way about what you can do: If you don't think positive, you won't win[italics added]. (Hornby, Cowie, Crowther, & Crowther, 1995, p. 292).