When he began teaching at Cornell University, the Russian novelist Vladimir Nabokov said he knew just two things: One, life is beautiful, and two, life is sad. The reason life is sad, he said, is because it’s going to end.

Yet death, our most unwelcome visitor, can also do us a favour. It can remind us, the mourners, what’s most important.

As Jack Kerouac observed, “Pondering on death, with or without wine – brings enlightenment.”

Too many of us spend our days moving with the hustling crowd, mindlessly doing more or less what everyone else is doing, acting as if we have all the time in the world. That is, until we get a wake-up call, and learn that someone close to us has had a bad accident or is suddenly very ill.

Increased awareness of our own mortality needn’t lead to fear and anxiety, however. We can use it as an opportunity to answer the question posed by poet Mary Oliver, “Tell me, what is it you plan to do with your one wild and precious life?”

Do you know? Or are you so consumed with projects, deadlines, and responsibilities that you haven’t given it much thought lately?

Meanwhile, the clock is ticking. And this realisation is a good thing.

Viewed from the prospect of eternity, we are really no more durable than the mayfly. Many spend their time just as frivolously. Others are bored. As author Susan Ertz quipped, “Millions long for immortality who don’t know what to do with themselves on a rainy Sunday afternoon.”

Greek mythology, on the other hand, gives us the story of Tithonus, a Trojan who was granted immortality by the gods but grew to hate his life.

Whatever path he chose, he could always take it later. Whatever options he faced, ultimately he could have them all. Time became meaningless, oppressive even. He lost his ardor for life. In the end, he petitioned Zeus to release him from eternity. He begged for mortality so that, once again, his choices might matter.

Each of us has been granted an incomparable gift, a brief stay on this little blue ball. How will you spend it? To what end will you use it?

These are the most important questions we can ask ourselves. And the answers can be read in the way we live our lives.

“Death is not the greatest loss,” Norman Cousins warned. “The greatest loss is what dies inside us while we live.”

Doctors generally observe that “terminal” patients who have truly lived their lives – who have strived and loved and taken risks – generally have an easier time with their dying.

Patients in nursing homes routinely express more regret for the chances they never took than the ones that worked out poorly.

Singer Bono, nominated for the Nobel Peace Prize and granted numerous awards for his activism for world poverty, said in a recent interview, “I’m tired of dreaming. I’m into doing at the moment.”

He is someone who has chosen to live life on his own terms and in service to the values that matter to him most. It is unlikely that you or I will ever accomplish as much. But that’s okay.

For most of us, born without the immense talents of a da Vinci or Beethoven or Lincoln, the true measure of our lives is not what we achieve – and certainly not what we accumulate – but rather who we are, the number of people we touch, and what is grieved in our absence.

As the novelist E.M. Forster observed, “Death destroys a man, but the idea of death saves him. “