If you right now, if you are dreaming, if you are having a nightmare, and if you having a terrible experience. From the objective point of view, you cannot say whatever you are dreaming such as some bulldozer being driven over you. You cannot say it does not exist because you are experiencing it. The bulldozer is about to roll over you. But at the same time you cannot also say it exist because in reality you are sleeping completely secure on your bed without even moving one inch. According to the Buddhist path you looking at me and me looking at you is really having an experience of bulldozer rolling over you. And ours is much worse than bulldozer actually. Whether it is obvious or not obvious there is a constant fear of all kinds. We have a constant fear because of the uncertainty.