On a recent air trip, the plane lurched, suddenly lost altitude and shook violently. Many passengers screamed. The pilot told anyone standing to drop to the floor. It was a terrifying moment for everyone, and one I have never experienced before, after almost a half century of air travel.

I felt surprisingly tranquil. None of us knew what might happen next, but everyone on that plane wondered if this was the end. I held my wife’s hand, thinking that if we were to plunge to our deaths, I wanted to be connected to her. I thought that if this was my time, so be it.

Later my wife told me that she was praying that God would spare her — “I want more time with my new grandchildren,” she pleaded. Many others in the plane later shared that they experienced extreme panic. It felt like a moment that we will all face one day — although thankfully it wasn’t that day.

We all know, with complete certainty, that someday we will die — but how or when is a mystery. Yet, many of us don’t think much about it. Indeed, we try to avoid thinking about it.

In our Western culture, death is denied. It’s an enemy that sneaks up on us in the dark of night, when we are not looking, robs us of who we are and takes everything from us. Yet, isn’t death, like birth, a natural part of life?

Many religious people believe in the existence of heaven, where they hope they will go after they shed this mortal coil. Yet none of us have met any residents of the afterlife. So we can’t be completely certain, even if we have faith. Large numbers of Earth’s population believe in the concept of reincarnation, where they hope to be reborn into a new life. Interestingly, some surveys suggest that 20 percent of Americans believe in reincarnation. Throughout time, humans have pondered — what happens after we die?

In Tibetan Buddhism, practitioners meditate daily on death. They imagine themselves dying. The purpose — to remember that life is fleeting and that it’s important to make the most of our lives. It’s important to live our lives with intention. Its other purpose is to loosen our clinging to self.

The Buddha said that a lifetime is like a “flash of lightning in a summer sky.” As I grow older, this saying makes more sense to me. When I look back over the last 65 years of my life, it seems to have flashed by so quickly! Where did it go? When I recall epochs of my life— college, jobs, young children, their teenage years, and almost a quarter of century at The Everett Clinic, it all seems to have flown by like a speeding train.

I have had the privilege to work with many adults who had terminal cancer and were coming to the natural end of their lives. When they were diagnosed, they made radical alterations to their lives, realizing that their time was limited. I often thought, it’s not necessary to have a serious disease to evaluate how you are living your life. Indeed, better to reflect on that today, when all is well and change is easier to accomplish.

So what does it mean to reflect on your mortality? It means to live your life with intention.

Are you living your life in harmony with your values? What is important to you? Are those values at the center of your life?

Live your life in the here and now. The future is uncertain. Be present in the moment. Be the person that you want to be. Make sure that you communicate to loved ones what’s important.

If you have something that is important for you to do, do it. Don’t put things off to the uncertain future. If there is something that you want to do, find a way to do it now.

On that flight, in those frightening moments, I felt fear like everyone else. But I also felt peaceful in the knowledge that my life had purpose and meaning. And that it was filled with love and connection with family and friends.

Paul Schoenfeld is director of The Everett Clinic’s Center for Behavioral Health. His Family Talk Blog can be found at www.everettclinic.com/family-talk-blog.