Do things & be done. Seneca, Epistles 3.23.9-11

Punctuate your life with actions. Don't start things you never finish. When your time is past, have something finished you can offer.

Hic est locus solvendi aeris alieni. Possum enim tibi vocem Epicuri tui reddere et hanc epistulam liberare: molestum est semper vitam inchoare; aut si hoc modo magis sensus potest exprimi, male vivunt qui semper vivere incipiunt. Quare? inquis; desiderat enim explanationem ista vox. Quia semper illis imperfecta vita est; non potest autem stare paratus ad mortem qui modo incipit vivere. Id agendum est ut satis vixerimus: nemo hoc praestat qui orditur cum maxime vitam. Non est quod existimes paucos esse hos: propemodum omnes sunt. Quidam vero tunc incipiunt cum desinendum est. Si hoc iudicas mirum, adiciam quod magis admireris: quidam ante vivere desierunt quam inciperent. Vale.

Time to pay my debt. I could give you an utterance here from your boy Epicurus, and set this letter free: “It is a pain always to be starting your life.” But perhaps another aphorism will express my sentiment better: “They live ill who are always just beginning to live.” “How so?” you inquire, for this saying demands an explanation. Because for these people life is always unfinished. The man who barely begins to live can never stand prepared for death. We must act and be done if we are going to have lived: nobody can achieve life by constantly commencing it. Don't think that the ditherers are few: almost everyone does this. No sooner do they contrive to make another beginning than it's time to give up. If you find this surprising, I'll add an observation to shock you even more: some people cease to live before they ever even begin. Farewell.