" What if our worldline is just one of an infinite number of worldlines, some only slightly altered from the life we know, others drastically different? The Many-Worlds interpretation of quantum mechanics posits that all possible realities exist. That everything which has a probability of happening is happening. Everything that might have occurred in our past did occur, only in another universe. What if that’s true? What if we live in a fifth-dimensional probability space? What if we actually inhabit the multiverse, but our brains have evolved in such a way as to equip us with a firewall that limits what we perceive to a single universe? One worldline. The one we choose, moment to moment. It makes sense if you think about it. We couldn’t possibly contend with simultaneously observing all possible realities at once. So how do we access this 5-D probability space? And if we could, where would it take us? "

― Blake Crouch , Dark Matter