When Nelson Mandela died in 2013, a significant amount of people were shocked and confused. They were not in shock that he died, but that they were sure he died many years beforehand. This phenomenon became known as The Mandela Effect -- when a significant group of people all misremember the same thing.
There are a number of theories that can account for this phenomenon, one of the strongest being that we are constantly 'sliding' between parallel worlds, where the events remembered actually took place.
What do you think about The Mandela Effect? Real or just our brains processing information in a weird way?