This is a good video because it shows you how deep you can question seemingly obvious things. It also shows you the limits of rationality. Some of the conclusions reached by rational reasoning are just absurd. It's a strange loop. You end up in absurdity if you try to be completely rational.
Watch the video to see whether you have openly considered the question of what reality is. I don't think the way this video emphasizes physics and mathematics to arrive at the answer is particularly helpful, though. Introspection can work just as well to deconstruct your current belief system.