Mulder: It's the Mandela Effect.
Reggie: The what?
Mulder: The Mandela Effect, when someone has a memory that doesn't coincide with everyone else's or the facts, so named because some people have a memory that Nelson Mandela died in prison in the '80s when in fact he died a free man in 2013.
Reggie: No. It's called the Mengele Effect because people have the memory of Josef Mengele being apprehended in Ohio in 1970, so it's the Mengele Effect.
Mulder: The Mandela Effect has been an internet meme for almost a decade. It's ALWAYS been called that.
Reggie. Eh, see? You're having a Mengele Effect about the Mandela Effect.