This is from Sasha Sagan, daughter of Ann Druyan and Carl Sagan, remembering a time from her childhood when she began to understand mortality. Her parents told her:
“You are alive right this second. That is an amazing thing,” they told me. When you consider the nearly infinite number of forks in the road that lead to any single person being born, they said, you must be grateful that you’re you at this very second. Think of the enormous number of potential alternate universes where, for example, your great-great-grandparents never meet and you never come to be. Moreover, you have the pleasure of living on a planet where you have evolved to breathe the air, drink the water, and love the warmth of the closest star. You’re connected to the generations through DNA — and, even farther back, to the universe, because every cell in your body was cooked in the hearts of stars. We are star stuff, my dad famously said, and he made me feel that way.
My parents taught me that even though it’s not forever — because it’s not forever — being alive is a profoundly beautiful thing for which each of us should feel deeply grateful. If we lived forever it would not be so amazing.”