I've been carrying around a collection of Pema Chodron's writings and today I read this, which comes from "The Places That Scare You."
"The Buddha taught that there are three principal characteristics of human experience: impermanence, egolessness and suffering (or dissatisfaction.) The lives of all beings are marked by these three qualities. Recognizing these qualities to be real and true in our own experience helps us to relax with things as they are.
I feel gratitude to the Buddha for pointing out that what we struggle against all our lives can be acknowledged as ordinary experience. Life does continually go up and down. People and situations are unpredictable and so is everything else. Everybody knows the pain of getting what we don't want: sinners, saints, winners, losers. I feel gratitude that someone saw the truth and pointed out that we don't suffer this kind of pain because of our personal inability to get things right.
When I begin to doubt that I have what it takes to present with impermanence, egolessness and suffering, it uplifts me to remember that there is no cure for the facts of life. This teaching on the three marks of existence can motivate us to stop struggling, against the nature of reality. We can stop harming others and ourselves in our efforts to escape the alternation of pleasure and pain. We can relax and be fully present for our lives."