The authors examined the perceived and actual impact of exposure to conspiracy theories surrounding the death of Diana, Princess of Wales, in 1997. One group of undergraduate students rated their agreement and their classmates' perceived agreement with several statements about Diana's death. A second group of students from the same undergraduate population read material containing popular conspiracy theories about Diana's death before rating their own and others' agreement with the same statements and perceived retrospective attitudes (i.e., what they thought their own and others' attitudes were before reading the material). Results revealed that whereas participants in the second group accurately estimated others' attitude changes, they underestimated the extent to which their own attitudes were influenced.