This chapter examines how misinformation affects memory and reasoning, highlighting that memory often contains outdated or incorrect information that people may use in future decision-making. It emphasizes two key features of this phenomenon: the clear connection between the misinformation and its correction in memory, and the believability of both the misinformation and its correction, which are accepted as valid when no conflicting information is present. Overall, the chapter underscores the complexities of memory in a dynamic information environment.