Four things ~ a famous wisdom of the past
I want to repeat that famous statement, a famous wisdom of the past, which says, "Four things come not back: the spoken word, the arrows sped forth, opportunity lost, and time wasted." Time is the most important because in time only you have arrows, in time only you can speak, and in time only you can have opportunities. So that is the most fundamental resource that we have, and human life is nothing but a time span given to us to evolve out of this life into the other life.
Taken from the book "HeartSpeak 2004, Vol. 2", Chapter "Wisdom - the Proper Utilisation of Time", pg. 182, by Revered Chariji