The Mandela Effect, coined after Nelson Mandela’s supposed death in 1980, is a psychological effect where large groups of people misremember a specific detail or event. It’s one of the most prominent examples of psychological effects manipulating and shifting people’s memories, but certainly not the only example.

Ultimately, people’s memories just aren’t that great. What is meant to represent the realities of the past can, in reality, represent memories of memories, thoughts about memories, or variations of memory given by others. This is all due to the imperfect nature of the brain. There are countless studied effects that lead to something like the Mandela Effect.

Asch conformity, for example, describes humans’ likelihood to conform to a group’s views that they identify with over their own. The misinformation effect is another major example which describes the human tendency to want to believe and imagine the things they hear are real. 

In practice it’s not hard to see how these apply. The Monopoly man, for example, does not have a monocle. Although if one hasn’t thought about Monopoly for years and someone says “Wow, I definitely remember him having a monocle”, it’s not hard to see why others would agree. It’s fun to theorize, and it’s more interesting than just saying one’s memory was simply incorrect.

Avoiding the Mandela Effect and similar phenomenon is luckily easy enough. Staying critical of what one hears, fact-checking any relevant information one takes in, and understanding one’s own limitations are enough to not make these kinds of mistakes. The brain is not perfect, but what makes humans special is the ability to adapt.