Any theoretical physicist--or, I don't know, "Star Trek" writer--will tell you that the universe we inhabit is just one of a presumably infinite number of parallel universes: alternate realities that exist more or less ""out of sync" with our own. These universes are "there"--or maybe "here"--but not perceptible or reachable by us. Anyway, in theory, anything that could possibly happen in this universe does happen in one or more of these alternate universes. So if, for example, you go to a shopping center and, looking for a parking spot, turn left in the lot, then--in some other universe or universes--you actually turn right. In our universe, you arrive at work at 9:03 AM; in another, at 8:57; and in still another at 9:00--or at 11:14 because you decided to stop over at the apartment of your mistress (which in that universe you have) for a quickie.
The more you think about this kind of thing, the more your mind begins to reel. Because once you start considering the things that could change, you start to realize that the list of potential changes is, literally, endless--because in an infinite number of universes, literally anything can happen--and some would argue that every possibility must be true somewhere. Thus, not only is there a universe where I weigh five pounds more than I do here, but there is also one where I weigh five pounds less--and one where I am the fattest human being on the planet! And so are you! You live in New York? OK. But in universe B you live in New Jersey--as hard as that may be to accept--and in another, somehow, you've ended up in the Seychelles! Even though, in this universe, you don't even know where the Seychelles are!
In some universes, the Colonists lost the Revolutionary War with England, in some the South defeated the North, and in some Hitler won World War II. And if that's not disturbing enough, consider this: In some universe, you are Hitler!
I wonder if there is some parallel universe wherein parallel universes don't exist.
OK, time for a nap.