The reason why we ought to live today to the fullest has been vastly discussed and reasoned out. I offer no further thought to that. There always will be a messiah championing for that as penned by Rudyard Kipling in “IF” …..

“If you can fill the unforgiving minute
With sixty seconds’ worth of distance run,
Yours is the Earth and everything that’s in it,
And – which is more – you’ll be a Man, my son!………”

It however is true that people have to learn when their time has come to hung up their boots. As the Bible says in 1 Corinthians 13:11…..When I was a child, I spoke as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things….. It symbolizes maturity an acceptance of new responsibilities and roles. To again quote, this time the epic ‘Desiderata’ ….”Take kindly the counsel of the years, gracefully surrendering the things of youth”
Most people don’t grow up. Most people age. They acquire driving licenses , honor their credit cards, get married, have children, and call that maturity. That my friend is aging.