Hi BC123! I’m glad you decided to follow up on this from our chat this morning!
There has actually been a bit of serious academic work done on the question of whether we are living inside of a computer simulation. I’m not sure where the idea first originated — perhaps from “The Matrix”? Maybe something even earlier?
Anyway, I promised to give you some references that you could look at if you wanted to read more about this. Here they are:
Partway down, it mentions the Oxford University philosopher Nick Bostrum. I know Nick, and am good friends with one of his senior researcher, an Anders Sandberg. (In fact, Anders was at my birthday party last week!)
It isn’t just philosophers who look at such questions! For example, the NY Times article above also has a link to a paper by three physicists; the title of the article is “Constraints on the Universe as a Numerical Simulation.” It basically is about looking for ways to determine whether we are indeed living in a big computer simulation!
However, I should point out that this article may be a bit technical. Give it a look; if you find it a bit challenging, either write back with more questions… or you can look at this synopsis from The Telegraph from last November: http://tinyurl.com/ke77klb
I’m not sure if this gives a definitive answer to your question… but I hope that you at least have learned more about the possibility that we are living in a simulation!