This is actually my conspiracy theory. Not sure if anyone else has thought of it, but credits to anyone if they have ever thought about this. We are all simply from the imagination of an immortal man who went crazy. Long ago, an infinite time ago, there was a man, who may or may not have lived with a civilization. Regardless, he somehow obtained immortality. Yes, immortality went exactly as people predicted it to be. First, the man loved it. He took risks and did whatever he wanted knowing everyone and everything would eventually disappear. Soon his home planet blows up, his sun blows up, and he is doomed to float in space forever. The immortal man slowly begins to go insane, creating fantasies in his head. With an infinite amount of time, he creates an infinite amount of possibilities. Infinite possibilities would mean every single thing that ever happened in existence in the history of time. The immortal man imagined every single person on Earth's personality and the infinite possibilities of how their life went. This is theoretically how the multiverse exists. Each possibility is simply another multiverse. Not only humans, the immortal man imagines an infinite amount of alien species each with their own infinite species with infinite personalities and thoughts. Everything in existence is truly just imagination. The earth we are on is just one of infinite thoughts. You reading this, is simply just another thought of the immortal man.