What is the Mandela Effect?

Q. What is meant by the phrase “Mandela Effect”?

Adam answers:

The Mandela Effect is a sort of collective error in remembering history. This can be from stories that are repeated in error that then get spread around, or it can be from our collective tendency to think that our version of events is how something “should” be, or that our version makes the most sense.

An example of the Mandela Effect, and how it gets its name, is the often mistaken idea that Nelson Mandela died in prison in South Africa back in the 1980s. Nelson Mandela is dead, and he was in prison for a very long time, but he did not die in prison and in fact became president of South Africa after being released.

The Mandela Effect can commonly be seen in how people remember lines from a movie or lyrics to a song. A famous example is the often quoted line from the movie Casablanca, in which Humphrey Bogart says, “Play it again, Sam.” In reality, Bogart’s line was simply “Play it.” (His character does say it to Sam, however.) Our mis-remembrance of the line may be from our memory of when and why the line was said in the film (the song had been played earlier, and Bogart’s character did, in fact, want Sam to play it again) or it may be the many times we’ve heard it referred to in error over the years.