Shawn Indigo
We are constantly shifting into parallel realities and each one is so alike to the last that you almost can't tell. It's been happening since the beginning of the human experience I am pretty sure. One of the main reasons the Mandela Effect has popped up in our reality is because human beings have likely changed enough to make it possible. We somehow have passed a point where some are finding themselves aware consciously, in their awake mind so to speak, of some details from a previous universe. In other words we have always had amnesia to the changes that have likely been regularly switching around (changes in movie titles, spelling of words, the look of a countries flag, etc.) but now this amnesia symptom is wearing off and reality is seen closer to what it really is.