People can falsely remember horrific things

Our memories can be faulty in ways big and small. But perhaps the most infamous tragedy associated with false memory is the Satanic Panic.
For a time in the 1980s and 1990s, the media and others widely circulated the idea that roving gangs of Satanists in the U.S. regularly kidnapped and victimized people, especially children. Some of these tales originated from adults’ recollections of traumatic childhood memories that had been supposedly repressed and later recovered in therapy.
The Satanic gangs were never found and some people who recovered these memories in therapy eventually recanted them, alleging that their therapists had negligently encouraged the formation of these memories. But even to this day, there are people who appear to practice recovered memory therapy, as well as stories of people harmed by the practice.