Seneca - On the Shortness of Life
I am often filled with wonder when I see some men demanding the time of others and those from whom they ask it most indulgent. Both of them fix their eyes on the object of the request for time, neither of them on the time itself; just as if what is asked were nothing, what is given, nothing.
Men trifle with the most precious thing in the world; but they are blind to it because it is an incorporeal thing, because it does not come beneath the sight of the eyes, and for this reason it is counted a very cheap thing—nay, of almost no value at all.
Men set very great store by pensions and doles, and for these they hire out their labour or service or effort. But no one sets a value on time; all use it lavishly as if it cost nothing. But see how these same people clasp the knees of physicians if they fall ill and the danger of death draws nearer, see how ready they are, if threatened with capital punishment, to spend all their possessions in order to live!
So great is the inconsistency of their feelings. But if each one could have the number of his future years set before him as is possible in the case of the years that have passed, how alarmed those would be who saw only a few remaining, how sparing of them would they be! And yet it is easy to dispense an amount that is assured, no matter how small it may be; but that must be guarded more carefully which will fail you know not when.
read: On the Shortness of Life by Seneca