Conserve imagination. Marcus Aurelius 3.4.1-2
Save your imagination for the things that matter, to you. Make your schemes impervious to hidden motives and unpredictable outcomes. When people question your decisions, have simple answers for them.
Μὴ κατατρίψῃς τὸ ὑπολειπόμενον τοῦ βίου μέρος ἐν ταῖς περὶ ἑτέρων φαντασίαις, ὁπόταν μὴ τὴν ἀναφορὰν ἐπί τι κοινωφελὲς ποιῇ «ἤτοι γὰρ ἄλλου ἔργου στέρῃ». τουτέστι φανταζόμενος τί ὁ δεῖνα πράσσει καὶ τίνος ἕνεκεν καὶ τί λέγει καὶ τί ἐνθυμεῖται καὶ τί τεχνάζεται καὶ ὅσα τοιαῦτα ποιεῖ ἀπορρέμβεσθαι τῆς τοῦ ἰδίου ἡγεμονικοῦ παρατηρήσεως. χρὴ μὲν οὖν καὶ τὸ εἰκῇ καὶ μάτην ἐν τῷ εἱρμῷ τῶν φαντασιῶν περιίστασθαι, πολὺ δὲ μάλιστα τὸ περίεργον καὶ κακόηθες καὶ ἐθιστέον ἑαυτὸν μόνα φαντάζεσθαι, περὶ ὧν εἴ τις ἄφνω ἐπανέροιτο· τί νῦν διανοῇ; μετὰ παρρησίας παραχρῆμα ἂν ἀποκρίναιο ὅτι τὸ καὶ τό· ὡς ἐξ αὐτῶν εὐθὺς δῆλα εἶναι, ὅτι πάντα ἁπλᾶ καὶ εὐμενῆ καὶ ζῴου κοινωνικοῦ καὶ ἀμελοῦντος ἡδονικῶν ἢ καθάπαξ ἀπολαυστικῶν φαντασμάτων ἢ φιλονεικίας τινὸς ἢ βασκανίας καὶ ὑποψίας ἢ ἄλλου τινός, ἐφ̓ ᾧ ἂν ἐρυθριάσειας ἐξηγούμενος, ὅτι ἐν νῷ αὐτὸ εἶχες.
Do not waste the remaining portion of your life lost among schemes and dreams of others, unless perchance they offer some benefit in which you share, or their absence would deprive you of something actually valuable. What I mean to say: don't ask yourself why someone acts out, what purpose he has for parlous deeds, what counsel he utters and keeps back, what cunning plans he devises for himself. All these considerations sap your ability to heed your own inner ruler. Instead of pondering them, you must represent to yourself the vanity and foolishness evident in every series of schemes, considering your plans only in terms of what is customary, what is malicious, and what is superfluous—so that if any question arise suddenly, "What do you think?," you can answer immediately and frankly: "Thus and such." The result: your schemes will all be lucid, simple, and kind, coming from an animal whose evident ability to share shows no attachment to pleasure or wild imagination, or to any rivalry or envy or suspicion of others—for you would undoubtedly blush to catch yourself holding such things in your mind.