I am reading  some books by Stephen Levine. He has worked extensively with those who are dying, and writes about grief and loss. What he has found is that many arrive at the end of their life with regrets, wishing that they had done this or that, lived more fully here or there, realized their potential in this way or that. This has led him to emphasize living each moment fully, not limiting ourselves in this moment to our past or waiting for our future,  in order to have no regrets:

Most of life only lasts a moment. Then our life becomes a memory, a dream. We are only alive a millisecond at at time. This moment! Or as one teacher put it, holding his thumb and forefinger about a quarter inch apart, “All of life is only just this much–just a moment in time.” When we open to this very instant in which awareness produces consciousness, we are fully alive. Completely preent. Big-minded.

To the degree we are present for “just this much” this living moment, we are alive. Otherwise we numb to the vibrancy and beg upon our deathbed for one more chance.

Most think that living a “full life” means living into old age. But if you are not alive this moment, what makes you think you’ll be alive then? To live fully is to be filled with this moment. Present for this millisecond, this day, this week, this life.”

Stephen and Ondrea Levine, Embracing the Beloved

In this he echoes the words of Daniel Gilbert in his book Stumbling on Happiness. He too draws attention to not neglecting to do the things we want, to dare to choose certain paths that open up in front of us.

... most people think they will regret foolish actions more than foolish inactions. But studies show that nine out of ten people are wrong. Indeed, in the long run, people of every walk of life seem to regret not having done things much more than they regret things they did.