Do you believe it is physically possible for an extremely advanced enough civilization to build a simulation where conscious simulated beings live unaware that they are simulated. Yes|No
If the answer is no, well then you can stop reading because this wont interest you further.
If the answer is yes then you may agree that over all the time in the universe bang to heat death there will be at least once such civilization that gets to this level.
If they get to this level running such simulation it is not unreasonable to assume they wont stop to only run a single one. Part of the usefulness in Simulations is that you can run many next to each other and if you have the knowledge and means already then why not.
So if you answered yes in the first question you are now at a not unreasonable hypothetical of at some point in all of time a real world society is running many simulated world.
In many ways one can argue that many simulated worlds is already a multiverse.
But lets continue with a conservative definition and say simulated world is not a separate universe,
there can only be one true real world. Which at some point may run simulations that can hold conscious lives.
You are a conscious entity, you believe to be born in this world but you never knew any better or else.
There are near infinite locations and times in the real world where you could have be born/started to exist
But a single simulation already doubles all of time and space, there are infinitely more locations and times your consciousness could manifestation in one of the many simulated worlds.
So getting to this point. What are the odds your conscious manifested inside a human embryo during one of the most interesting scientific times of human history and it also being the one real non simulated world?