Diagnosed with terminal cancer, Oliver Sacks has written a poignant essay on the last stage of his life. It's brave in its equanimity yet eloquent in its sense of loss, especially about the deaths of others, unique individuals who can never be replaced. I'm moved by his detachment, his serene faith in a future he will not see, and above all his affirmation of living a full life, not only in retrospect but also in his time remaining.