The essence of this world is impermanence. This is the true nature of this world. Who can change this? Today everything is good, tomorrow it will be very difficult. It is the natural way things are. Today we are healthy, tomorrow we are sick; for a while we are very wealthy, then we become like beggars. Oh, we may be beggars and later become kings. This is just the way it is. This is the result of the two fundamental laws of this world, the infallibility of cause and effect, and the true nature of this world which is impermanence.