Letters 98.10

But men are so wayward, and so forgetful of their goal and of the point toward which every day jostles them, that they are surprised at losing anything, although some day they are bound to lose everything. Anything of which you are entitled the owner is in your possession but is not your own; for there is no strength in that which is weak, nor anything lasting and invincible in that which is frail. We must lose our lives as surely as we lose our property, and this, if we understand the truth, is itself a consolation. Lose it with equanimity; for you must lose your life also.

Seneca, Letters to Lucilius 98.10, translated by Richard Mott Gummere