“Is there any way to be sure that your whole life has not been a dream? I don't think that there is. Typically we call some experiences "dreams" and others "reality" by contrasting them. Experiences that we call "real" are consistent and predictable. For example, people don't just get up and fly away in "real life" while they sometimes do in dreams. And it is not unusual for the experiences we have in dreams to jump around from one time and place to another, while those events we call "real" do not. But if your whole life has been a dream, then there is nothing to contrast these experiences with. In this case, the "dreams" that you recall each night are just dreams within the dream. And that contrast still holds. Even if your whole life has been a dream you could distinguish your nightly dreams from your "waking experiences" much of the time. But how do you know that you are not in Neo's predicament- that even your waking experiences are simply more dreams- just more predictable ones? Morpheus's suggestion seems correct. If you have never awakened from the dream to see what "real life" is actually like, you would have absolutely no way to discern that you are dreaming.”