Last April, Sasha Sagan, the daughter of the late Carl Sagan and Cosmos producer Ann Druyan, wrote a beautiful essay called “Lessons of Immortality and Mortality From My Father, Carl Sagan” chronicling what her parents  taught her about life and death and the kind of immortality that is congruent with reality.

One day when I was still very young, I asked my father about his parents. I knew my maternal grandparents intimately, but I wanted to know why I had never met his parents.

“Because they died,” he said wistfully.

“Will you ever see them again?” I asked.

He considered his answer carefully. Finally, he said that there was nothing he would like more in the world than to see his mother and father again, but that he had no reason — and no evidence — to support the idea of an afterlife, so he couldn’t give in to the temptation.

“Why?”

Then he told me, very tenderly, that it can be dangerous to believe things just because you want them to be true. You can get tricked if you don’t question yourself and others, especially people in a position of authority. He told me that anything that’s truly real can stand up to scrutiny.

Sasha continues with the story of her father’s papers and memorabilia, “keepsakes and manuscripts — the evidence of a great life lived by a great man and all it contained,” and their journey, ending at the Library of Congress, where, “In the way couples sometimes renew their vows, we renewed our grief.”

And in that moment my father was both so alive in the minds of those who loved him and so painfully gone. The conundrum of mortality and immortality was crystallized for me in the Library of Congress that day, but it’s the same paradox of our small place in the enormous universe that my parents first taught me in the Sphinx Head Tomb.

As brilliant and influential as her father was, Sasha’s story is also our story:  Lessons are taught; the pain of loss is suffered; the reality of death is accepted; the memories of those we love are honored and cherished, even through the sorrow.

What lessons were you taught by the people for whom you grieve?