Indeed, it is precisely because life is unpredictable that we have the "duty of delight," as Dorothy Day, founder of the Catholic Worker movement, called it, a responsibility to relish, cherish, and value the gifts we have been given so that when they are taken away — through death or other changes that life's impermanence brings our way — we will not have to also bear the pain of having failed to appreciate what we had.
— M. J. Ryan, The Happiness Makeover