3 Having then these precepts and promises, why seek we on earth for “good days,” where we cannot find them? For I know that you do seek them, when you are either sick, or in any of the tribulations, which in this world abound. For when life draws towards its close, the old man is full of complaints, and with no joys. Amid all the tribulations by which mankind is worn away, men seek for nothing but “good days,” and wish for a long life, which here they cannot have. For even a man's long life is narrowed within so short a span to the wide extent of all ages, as if it were but one drop to the whole sea.
What then is man's life, even that which is called a long one? They call that a long life, which even in this world's course is short; and as I have said, groans abound even unto the decrepitude of old age. This at the most is but brief, and of short duration; and yet how eagerly is it sought by men, with how great diligence, with how great toil, with how great carefulness, with how great watchfulness, with how great labour do men seek to live here for a long time, and to grow old.
And yet this very living long, what is it but running to the end? You had yesterday, and you wish also to have tomorrow. But when this day and tomorrow are passed, you have them not. Therefore you wish for the day to break, that that may draw near to you whither you have no wish to come. You make some annual festival with your friends, and hear it there said to you by your well-wishers, “May you live many years,” you wish that what they have said, may come to pass. What? Do you wish that years and years may come, and the end of these years come not? Your wishes are contrary to one another; you wish to walk on, and do not wish to reach the end.
Source: Sermons on Selected Lessons of the New Testament (New Advent)