If the universe is 14.5 billion years old and is as vast and incomprehensibly big as we think it is, and if we as a species are within a couple hundred years of being able to effectively simulate reality, and you consider all the possible simulations that might run on computer hardware of the future, then the probability that we are either brains in a vat, or some other type of computer simulation, seems considerably higher than the probability that it is actually the year 2015 and we are technologically close to, but haven't quite mastered virtual reality simulations. How would you differentiate this reality compared to a simulation of human society in 2015 as created by some human 1000 years in the future? We're "The Sims" from a game of the future.