Is our world real?

I recently read the article Are We Living in a Computer Simulation? in class today.  It talked about how we are just characters in some giant computer game and we wouldn't know it. The idea is the universe is a simulation. I find this theory to be interesting because I have never thought to myself before , "Am I just a character in a video game and someone else is controlling it?" I don't believe in this theory because I believe that nature controls us. I believe that our world is real because we live in a physical world and I do really exist.