In recent years I've been irritated by how often people misuse the phrase "cognitive dissonance." Understood correctly, it's a powerful and important theory about one of the things that can drive people to change their beliefs and/or their behaviors -- and which can be exploited by others for this purpose, including in underhanded and unethical ways, as often is practiced by cults for instance. But the colloquial usage completely fails to capture this dynamic aspect of the concept, reducing it instead to a sort of highfalutin insult.
I saw another example of this in the latest Savage Love column, and submitted this comment:
While the column may be a rerun, unfortunately an inaccurate idea expressed therein seems to be as widespread now as when it was first published: the definition, "cognitive dissonance: the holding of mutually exclusive beliefs."
As Wikipedia explains, "In modern psychology, cognitive dissonance is the feeling of discomfort when simultaneously holding two or more conflicting cognitions." Note the operative phrase, "feeling of discomfort." It's irrelevant whether SOMEONE ELSE perceives you to be holding mutually exclusive beliefs; what matters is whether YOU feel discomfort because YOU perceive a discrepancy. Leon Festinger, the author of the theory of cognitive dissonance, considered this effect important because people have a drive to REDUCE cognitive dissonance. You can't be driven to reduce a discrepancy that only other people, not you, perceive. Without this ingredient, it's reduced to an epithet, a pseudoscientific way of saying, "I think you're inconsistent!"