You have illusions and see the exceedingly temporary world as undying and permanent. When you look around yourself at the world, you see it as stable to a degree, and constant. Since looking with the same view you also consider your own transient self to be constant, you only take fright at Doomsday. You are only frightened at that as though you were going to live till then.
Use your reason! You and your personal world are perpetually subject to the blows of death and decline. Your illusion and sophistry resemble this comparison: if you have a mirror and hold it up to a house or a town or a garden, their images will appear in it. If the mirror is moved the tiniest amount or the smallest change occurs to it, the images become confused and distorted. The fact that the actual house, town or garden outside the mirror continue and are constant is of no avail to you, for the house in the mirror in your hand and your town and garden are only in the scale and proportions which the mirror gives you.
Your life is the mirror. The support and mirror of your world and its centre is your life. Every minute it is possible that the house, town, and garden will die and be destroyed, their condition is such that any minute they may collapse on your head and your doomsday will come. Since it is thus, do not burden this life and world of yours with loads they cannot raise and support!