Nothing unnerves us more than false memories. When people heard about the collective false belief that Nelson Mandela perished in 1980, they called it evidence of a parallel universe. Others thought it was a government conspiracy.
Psychologists, on the other hand, have a more rational explanation for the Mandela Effect. Individual humans can misremember things for any number of reasons. Their speculation may have grown out of hand, or they conflated rumor with reality. Then, when they spread their “knowledge” to others, the group accepts it out of a desire to conform. Technological advances may increase the Mandela Effect’s frequency.
Infographic Source: https://www.online-psychology-degrees.org/mandela-effect/