[Egekrusher]

There is also a theory that says that in reality, we don't truly exist.

We are all one atomic particle, all matter in the universe is one particle. Time is an illusion caused by parrallel universes, an infinite number of universes that all spawn from this one particle. All of the events that take place in our space/time continuum are just one of infinite possibilities that are being played out by that one atom. All of the parallel universes out there are the other possible outcomes of what could have happened if that particle would have taken a different course.

An actual scientific theory.

There are 4 different possibilities when it comes to parallel universes. That is one of the 4 possiblities.

Now, recently scientists have proven that there are, for a fact, parallel universes. They just don't know which of the four types it is.