Letters 108.27

Why “choicest day”? Because what’s to come is unsure. Why “choicest day”? Because in our youth we are able to learn; we can bend to nobler purposes minds that are ready and still pliable; because this is the time for work, the time for keeping our minds busied in study and in exercising our bodies with useful effort; for that which remains is more sluggish and lacking in spirit—nearer the end.

Let us therefore strive with all courage, omitting attractions by the way; let us struggle with a single purpose, lest, when we are left behind, we comprehend too late the speed of quick-flying time, whose course we cannot stay. Let every day, as soon as it comes, be welcome as being the choicest, and let it be made our own possession.

Seneca, Letters to Lucilius 108.27, translated by Richard Mott Gummere