For eight years, Bronnie Ware was an in-home caregiver who looked after people who were dying. Her clients knew they were severely ill, and most were in the last three to 12 weeks of their lives.

But Ware gradually realized that the most important role she was playing was not physical, but emotional. She was there to listen, and she catalogued those intimate reflections her book, “The Top Five Regrets of the Dying.”

In their last days, many of her patients shared with her their regrets. The most common answer, according to Ware, was: “I wish I had the courage to live a life true to myself, not the life others expected of me.”

“It is very important to try and honor at least some of your dreams along the way before it is too late,” she writes. “Health brings a freedom very few realize, until they no longer have it.”

As a psychologist, this is something I see all the time with my patients. I always tell them that to boost my happiness and stop the clock on regret, I work on developing an appreciation for time.

Why time is the most valuable resource we have

In the daily grind, it’s easy to fall out of alignment with what is most important to you.

But living with an awareness of our own mortality fundamentally changes what we value and how we choose to use our time. It unmasks the frivolous, empty pursuits our culture often validates.

Does the response to your social media post really matter? Does it matter what car you drive? Does it matter that a friend group boxes you out of their social circle? If they let you in, do you really want to spend your precious time with them?

Fully embracing the fact that we are not going to live forever brings our values into sharp focus. When the dermatologist tells you she wants to biopsy an irregular-shaped mark because it looks precancerous, you are likely are not thinking about the high-achieving image you have carefully constructed to present to your colleagues.

Once you recognize that time is the most precious of all commodities, there will no longer be a disconnect between the choices you want to make and the choices you actually make.

What will you regret at the end of your life?

You don’t need to wait and then look back and wish you had done things differently. You can start with a clean slate today. Simply ask yourself what you regret at this exact moment.

If you wish you were more present for your two-year-old daughter, you are likely going to have that same regret four decades from now. If you regret opting for the comfort and familiarity of your current job rather than reaching for the stars, you will likely have a similar regret down the road.

The big difference between now and then is that you have the ability to do something about it today.

Here’s another simple exercise that I love: When you say goodbye to someone, say it as if you might not ever see them again. Say goodbye in a way that you demonstrate the gratitude you have for the time you have spent together.

Start with one person today. Tomorrow, two. Work your way until it becomes part of your everyday routine.

** Michael Gervais is a high-performance psychologist and author

CNBC