Gratitude ... goes beyond the "mine" and "thine" and claims the truth that all of life is a pure gift. In the past I always thought of gratitude as a spontaneous response to the awareness of gifts received, but now I realize that gratitude can also be lived as a discipline. The discipline of gratitude is the explicit effort to acknowledge that all I am and have is given to me as a gift of love, a gift to be celebrated with joy.
-Henri J. M. Nouwen