Truly understanding impermanence means recognizing both the nature of change inherent in all phenomena and the extraordinary opportunity to train your mind toward liberation. Reflecting, you begin to see that you must not waste precious time. As soon as you were born, it was guaranteed that you will eventually die. This inevitable death will deprive you of any opportunity to practice. Begin to realize clearly that, instead of putting off practice until some future time, you must begin right now to extract some meaningful essence from your human birth. The point of understanding impermanence is not to feel sad about it, but to use it as an incentive to overcome laziness.
~ ~ Lama Tharchin Rinpoche ~ An excerpt from A Commentary on the Dudjom Tersar Ngondro: The Preliminary Practice of the New Treasures of Dudjom