Four experiments examined projection and egocentrism in people's expectations about how a treatment they tried would impact others. In Experiment 1, people's expectations and recommendations for others aligned heavily with their own experience even though they directly witnessed a co-participant's contradictory experience. Experiments 2 and 3 examined potential mechanisms for the egocentrism. In Experiment 4, egocentrism persisted even when participants saw two co-participants have experiences that contradicted their own, except when the dependent measure about expectations was statistically framed. Implications for the literature on false consensus and for understanding the persistence of beliefs in ineffective treatments are discussed.