What if you were actually thousands of years old, brainwashed at birth, and nothing is real. All of humanity has been wiped out, your the last one alive. Everything you see is really just a figment of your imagination. Everyone, besides a few robots programmed to think they are real without a doubt, is in your mind. The zombie apocalypse is your brain starting to awaken, and the bots starting to awaken also. The bots are bad, so are the zombies. So really, you don't know whether or not your real. You don't know if your a bot, or an imagination, and you don't know if your the "chosen" one.
Haven't really thought out a plot and it's a bit confusing, but it does make sense.... In an odd way. :