Hold every hour in your grasp

Hold every hour in your grasp. Lay hold of today's task, and you will not need to depend so much upon tomorrow's. While we are postponing, life speeds by. Nothing is ours, except time. We were entrusted by nature with the ownership of this single thing, so fleeting and slippery that anyone who will can oust us from possession. What fools these mortals be! They allow the cheapest and most useless things, which can easily be replaced, to be charged in the reckoning, after they have acquired them; but they never regard themselves as in debt when they have received some of that precious commodity—time! And yet time is the one loan which even a grateful recipient cannot repay.

                  ~ Seneca, Volume IV, Epistles 1-65 via Letters of Note