Time Takes on Urgency During Aging

As I age, now into retirement for seven-plus months, my changing perception of the passage of time is causing me to reevaluate how best to spend it.  For one, with me it no longer seems that the future is as vast and wide open as it was during my youth...that's being pretty realistic, I think.  You can be pretty healthy...even athletic in your "golden" years, as Paul, an acquaintance in his 80's, demonstrated, and then quickly succumb to an aggressive cancer, organ failure or other ailment.  After my open-heart surgery four years ago, I recovered to the level of being once again able to do Parkrun 5Ks.  On one such run the following year, Paul and I found ourselves running side-by-side, and he revealed he had run many marathons in his past. He seemed very fit and at the close of our little talk, he then sped off and finished the 5K well ahead of me.  I hadn't seen Paul in a long time and just recently discovered that he had died this past February from pancreatic cancer.  Very sad, but that's a common part of being a senior: you're going along just fine, with what seems like an open future stretching out before you...and then, poof!, just like that, you're gone.  Well, that's one rapidly shifting perception of time that's recently affected me.  The other is my increased sensitivity to how, with each new day, I have things I want to do and how so-called "urgencies" that crop up tend to crowd them out, making me feel selfish and guilty should I assert myself and carve out my own time for them.  This also has to do with my sense that I don't have forever in this world to pursue my own interests and goals in spite of how well I physically feel or what encouraging words my doctors say...I'm developing my own personal sense of urgency regarding these things...