It's just data processing. If it wasn't trained to speak like a human you would have no problems in seeing it's a machine. Try to ask it to create a joke about some topics and you can easily see it's just a robot. The lesson to take is not that we are not prepared to assume other type of intelligence is "real". The lesson here is that we humans fool ourselves when we are exposed to some kinds of data. Remember, you can simulate an AI with pen an paper, and the speed at which you simulate it doens't make a difference, it's provably deterministic (a part from randomness that doesn't change a thing for the point). Good look in proving that humans are deterministic.