If you have read my post about agnosticism, (If you haven't you should!), you know that I question our existence, our origin, and the universe.
There is a very interesting list on Listverse showing different theories about the fact we could be indeed a simulation:
"Philosophers as far back as Plato millennia ago speculated that what we
see may not be real at all. With the advent of computers, the idea took
on new life, especially in recent years, with films like Inception, Dark City, and the Matrix trilogy. Is it possible that the world is just a computer simulation?"
Read the list on Listverse