Life is a river. Marcus Aurelius 4.43

Life is a stream in which things move, bearing us and our cares along in an interchange of momentum that is always dynamic, evolving, escaping every attempt at total control. Ride the wave, for you will never own it.

Ποταμός τίς ἐστι τῶν γινομένων καὶ ῥεῦμα βίαιον ὁ αἰών· ἅμα τε γὰρ ὤφθη ἕκαστον, καὶ παρενήνεκται, καὶ ἄλλο παραφέρεται, τὸ δὲ ἐνεχθήσεται.

Life is a river of events whose current runs strong. No sooner has one thing appeared and passed on, than another comes whirling by: it too shall wash away.