Section 9: Postponing Life Is Dangerous explained simply

IX. Can anything be mentioned which is more insane than the ideas of leisure of those people who boast of their worldly wisdom? They live laboriously, in order that they may live better; they fit themselves out for life at the expense of life itself, and cast their thoughts a long way forwards: yet postponement is the greatest waste of life: it wrings day after day from us, and takes away the present by promising something hereafter: there is no such obstacle to true living as waiting, which loses to-day while it is depending on the morrow. You dispose of that which is in the hand of Fortune, and you let go that which is in your own. Whither are you looking, whither are you stretching forward? everything future is uncertain: live now straightway. See how the greatest of bards cries to you and sings in wholesome verse as though inspired with celestial fire:— “The best of wretched mortals’ days is that Which is the first to fly.” Why do you hesitate, says he, why do you stand back? unless you seize it it will have fled: and even if you do seize it, it will still fly. Our swiftness in making use of our time ought therefore to vie with the swiftness of time itself, and we ought to drink of it as we should of a fast-running torrent which will not be always running. The poet, too, admirably satirizes our boundless thoughts, when he says, not “the first age,” but “the first day.” Why are you careless and slow while time is flying so fast, and why do you spread out before yourself a vision of long months and years, as many as your greediness requires? he talks with you about one day, and that a fast-fleeting one. There can, then, be no doubt that the best days are those which fly first for wretched, that is, for busy mortals, whose minds are still in their childhood when old age comes upon them, and they reach it unprepared and without arms to combat it. They have never looked forward: they have all of a sudden stumbled upon old age: they never noticed that it was stealing upon them day by day. As conversation, or reading, or deep thought deceives travellers, and they find themselves at their journey’s end before they knew that it was drawing near, so in this fast and never-ceasing journey of life, which we make at the same pace whether we are asleep or awake, busy people never notice that they are moving till they are at the end of it.