From Stephen Cave, author of "Immortality: The Quest to Live Forever and How It Drives Civilization", comes my favorite metaphor about life so far:
Just as a book is bounded by its covers by a beginning and end, so our lives are bounded by birth and death. And even though a book is limited by a beginning and end, it can encompass distant landscapes, exotic figures, fantastic adventures. And even though a book is limited by a beginning and end, the characters within it know no horizons.
They only know the moments that make up their story, even when the book is closed. And so the characters of a book are not afraid of reaching the last page. Long John Silver is not afraid of you finishing your copy of “Treasure Island.” And so it should be with us. Imagine the book of your life, its covers, its beginning and end, your birth and your death. You can only know the moments in between, the moments that make up your life.
It makes no sense for you to fear what is outside of those covers, whether before your birth or after your death. And you needn’t worry how long the book is or whether it’s a comic strip or an epic. The only thing that matters is that you make it a good story.