If you reflect on death then there is nothing you will need. Always keep death in mind. Once the conviction that everything is impermanent, the recognition that existence is very fragile, and the awareness that death is an ever-present threat, once these things have truly taken root in your mind you will stop hankering after life's ordinary compulsions. But if you don't reflect deeply enough on death and impermanence your lack of perspective will make it difficult to rid yourself of life's more futile concerns. Your tendency always to want more than you need will continue. Even though you have enough to eat you will want ever more delicious food. Despite having enough clothes and an adequate place to live you will keep thinking about getting something better or more fashionable to wear and a bigger more comfortable house. Although you may already have a partner or lover you will be constantly on the lookout for someone better. These are all signs that you are not remembering how close death really is, all the time. Why would you invest all that energy on those plans for the future if you are not somehow blindly convinced that you are still sure to be in this world for a long time to come. The great practitioners of the past describe themselves as yogis with the thought of impermanence planted firmly in their hearts. They saw clearly the futility of ordinary pursuits. There minds were entirely turned towards the dharma. Their practice of the dharma was based upon a frugal life inspired by the thought of their own death which they knew would take place, somewhere in a deserted cave. All these great practitioners, of course, are now dead... Such a far-sighted and profound perspective can take hold within you. It is the result of being constantly mindful of death. Mindfulness of death is a nectar-like medicine that restores you to health and a sentinel that watches over the discipline of your practice, never letting it stray into distractions.
Dilgo Khyentse Rinpoche