Don’t let yourself forget how many doctors have died, after furrowing their brows over how many deathbeds. How many astrologers, after pompous forecasts about others’ ends. How many philosophers, after endless disquisitions on death and immortality. How many warriors, after inflicting thousands of casualties themselves. How many tyrants, after abusing the power of life and death atrociously, as if they were themselves immortal.
How many whole cities have met their end: Helike, Pompeii, Herculaneum, and countless others.
And all the ones you know yourself, one after another. One who laid out another for burial, and was buried himself, and then the man who buried him — all in the same short space of time.

[Ἐννοεῖν συνεχῶς πόσοι μὲν ἰατροὶ ἀποτεθνήκασι, πολλάκις τὰς ὀφρῦς ὑπὲρ τῶν ἀρρώστων συσπάσαντες: πόσοι δὲ μαθηματικοί, ἄλλων θανάτους ὥς τι μέγα προειπόντες: πόσοι δὲ φιλόσοφοι, περὶ θανάτου ἢ ἀθανασίας μυρία διατεινάμενοι: πόσοι δὲ ἀριστεῖς, πολλοὺς ἀποκτείναντες: πόσοι δὲ τύραννοι, ἐξουσίᾳ ψυχῶν μετὰ δεινοῦ φρυάγματος ὡς ἀθάνατοι κεχρημένοι: πόσαι δὲ πόλεις ὅλαι, ἵν̓ οὕτως εἴπω, τεθνήκασιν, Ἑλίκη καὶ Πομπήιοι καὶ Ἡρκλᾶνον καὶ ἄλλαι ἀναρίθμητοι. ἔπιθι δὲ καὶ ὅσους οἶδας, ἄλλον ἐπ̓ ἄλλῳ: ὁ μὲν τοῦτον κηδεύσας εἶτα ἐξετάθη, ὁ δὲ ἐκεῖνον, πάντα δὲ ἐν βραχεῖ.]

Marcus Aurelius (AD 121–180) Roman emperor (161–180), Stoic philosopher

Meditations [To Himself; Τὰ εἰς ἑαυτόν], Book 4, ch. 48 (4.48) (AD 161-180) [tr. Hays (2003)]
    (Source)

Helice (Helike, Ἑλίκη) was a town in Greece destroyed by an earthquake and tsunami in AD 373. Herculaneum and Pompeii were towns in southern Italy destroyed by an eruption of Mt Vesuvius in AD 79.

(Source (Greek)). Alternate translations:

Let it be thy perpetual meditation, how many physicians who once looked so grim, and so tetrically shrunk their brows upon their patients, are dead and gone themselves. How many astrologers, after that in great ostentation they had foretold the death of some others, how many philosophers after so many elaborate tracts and volumes concerning either mortality or immortality; how many brave captains and commanders, after the death and slaughter of so many; how many kings and tyrants, after they had with such horror and insolency abused their power upon men's lives, as though themselves had been immortal; how many, that I may so speak, whole cities both men and towns: Helice, Pompeii, Herculaneum, and others innumerable are dead and gone. Run them over also, whom thou thyself, one after another, hast known in thy time to drop away. Such and such a one took care of such and such a one's burial, and soon after was buried himself. So one, so another: and all things in a short time.
[tr. Casaubon (1634), 4.39]

Consider how many Physicians are Dead that us'd to value themselves upon the Cure of their Patients; How many Astrologers who thought themselves Great Men by foretelling the Death of others; How many Philosophers have gone the way of all Flesh, after all their Learned Disputes about dying, and Immortality; How many Field-Worthies, who had knock'd so many Mens Brains out ; How many Tyrants who manag'd the Power of Life and Death with as much Pride and Rigour, and as if themselves had been Immortal; How many Cities, if I may say so, have given up the Ghost: For Instance Helice in Greece, Pompeii, and Herculanum in Italy; not to mention many besides. Do but recollect your Acquaintance; And here you'll find People Managing and making way for Funerals; Mourning for their Friends, and giving Occasion for the same Office themselves. And all within a small Compass of Time.
[tr. Collier (1701)]

Consider frequently how many physicians, who had often knit their brows on discovering the prognostics of death in their patients, have at last yielded to death themselves: And how many astrologers, after foretelling the deaths of others, with great ostentation of their art; and how many philosophers, after they had made many long dissertations upon death and immortality; how many warriors, after they had slaughtered multitudes; how many tyrants, after they had exercised their power of life and death with horrid pride, as if they had been immortal; nay, how many whole cities, if I may so speak, are dead: Helice, Pompeii, Herculanum, and others innumerable. Then run over those whom, in a series, you have known, one taking care of the funeral of another, and then buried by a third, and all this in a short time.
[tr. Hutcheson/Moor (1742)]

Consider how many physicians have died, after having with contracted eye-brows and great solemnity pronounced the death of so many patients: -- how many astrologers, who thought it a great matter to foretell the fate of others: -- how many philosophers, after all their disputes about death and immortality: -- how many heroes, renowned for slaughter: -- how many tyrants, after exercising their power of life and death with the most ferocious insolence, as if they themselves were immortal! Nay, how many cities (if I may be allowed the expression) are dead and buried in their own ruins! Helice, Pompeii, and Herculaneum, and others without number.
Recollect also how many amongst your own acquaintance, whom, after attending the funerals of their friends, you have seen carried to their graves; and this within a short space of time.
[tr. Graves (1792), 4.39]

Think continually how many physicians are dead after often contracting their eyebrows over the sick; and how many astrologers after predicting with great pretensions the deaths of others; and how many philosophers after endless discourses on death or immortality; how many heroes after killing thousands; and how many tyrants who have used their power over men's lives with terrible insolence, as if they were immortal; and how many cities are entirely dead, so to speak, Helice and Pompeii and Herculaneum, and others innumerable. Add to the reckoning all whom thou hast known, one after another. One man after burying another has been laid out dead, and another buries him; and all this in a short time.
[tr. Long (1862)]

Consider how many physicians are dead that used to knit their brows over their patients; how many astrologers who thought themselves great men by foretelling the death of others; how many philosophers have gone the way of all flesh, after all their learned disputes about dying and immortality; how many warriors, who had knocked so many men's brains out; how many tyrants, who managed the power of life and death with as much insolence, as if themselves had been immortal; how many cities, if I may say so, have given up the ghost: for instance, Helice in Greece, Pompeii and Herculaneum in Italy; not to mention many besides. Do but recollect your acquaintance, and here you will find one man closing another's eyes, then he himself is laid out, and this one by another. And all within a small compass of time.
[tr. Collier/Zimmern (1887)]

Constantly realise how many physicians are dead, who have often enough knit their brows over their patients; how many astrologers, who have pompously predicted others' deaths; philosophers, who have held disquisitions without end on death or immortality; mighty men, who have slain their thousands; tyrants, who in exercise of their prerogative of death have blustered as though they were Immortals; whole cities buried bodily, Helice, Pompeii, Herculaneum, and others without end. Then count up those whom you have known, one by one; how one buried another, was in his turn laid low, and another buried him; and all this in a little span!
[tr. Rendall (1898)]

Constantly consider how many physicians are dead and gone, who frequently knitted their brows over their patients; how many astrologers, who foretold the deaths of others with great ostentation of their art; how many philosophers, who wrote endlessly on death and immortality; how many warriors, who slew their thousands; and how many tyrants, who used their power of life and death with cruel wantonness, as though they had been immortal. How many whole cities, if I may so speak, are dead: Helice and Pompeii and Herculaneum, and others past counting. Tell over next all those you have known, one after the other: think how one buried his fellow, then lay dead himself, to be buried by a third. And all this within a little time.
[tr. Hutcheson/Chrystal (1902)]

Cease not to bear in mind how many physicians are dead after puckering up their brows so often over their patients; and how many astrologers after making a great parade of predicting the death of others; and how many philosophers after endless disquisitions on death and immortality; how many great captains after butchering thousands; how many tyrants after exercising with revolting insolence their power of life and death, as though themselves immortal; and how many entire cities are, if I may use the expression, dead, Helice and Pompeii and Herculaneum, and others without number.
Turn also to all, one after another, that come within thine own knowledge. One closed a friend's eyes and was then himself laid out, and the friend who closed his, he too was laid out -- and all this in a few short years.
[tr. Haines (Loeb) (1916)]

Think continually how many physicians have died, after often knitting their foreheads over their patients; how many astrologers after prophesying other men's deaths, as though to die were a great matter; how many philosophers after endless debate on death or survival after death; how many paladins after slaying their thousands; how many tyrants after using their power over men's lives with monstrous arrogance, as if themselves immortal; how many entire cities have, if I may use the term, died, Helice, Pompeii, Herculaneum, and others innumerable. Run over, too, the many also you know of, one after another. One followed this man's funeral and then was himself laid on the bier; another followed him, and all in a little while.
[tr. Farquharson (1944)]

Remind yourself constantly of all the physicians, now dead, who used to knit their brows over their ailing patients; of all the astrologers who so solemnly predicted their clients’ doom; the philosophers who expatiated so endlessly on death or immortality; the great commanders who slew their thousands; the despots who wielded powers of life and death with such terrible arrogance, as if themselves were gods who could never die; the whole cities which have perished completely, Helice, Pompeii, Herculaneum, and others without number. After that, recall one by one each of your own acquaintances; how one buried another, only to be laid low himself and buried in turn by a third, and all in so brief a space of time.
[tr. Staniforth (1964)]

Reflect constantly on how many physicians have died after knitting their brows again and again over the beds of the sick; and how many astrologers after foretelling the deaths of others as though death itself were some great thing; and how many philosophers after endless disputes about death and immortality; and how many heroes after slaying a multitude of others; and how many tyrants after exercising their power over life and death with fearful arrogance, as though they themselves would be immortal; and how many entire cities have, if one may use the word, died: Helice, Pompeii, Herculaneium and others without number. Also call before your mind, one after another, the many whom you yourself have known. This man, after paying his last respects to that, was then laid out himself, and the one who laid him out was laid out in his turn, and all in so short a time.
[tr. Hard (1997 ed.)]

Consider continually how many doctors have died, after often knitting their brows over their patients; how many astrologers, having foretold the deaths of others as if this were something important; how many philosophers, who contend endlessly about death and immortality [...] Go over how many people you have known, one after the other; one buried another and was then laid out for burial himself, and another another; all; in a short time.
[tr. Hard? (1997 ed.)]

Think constantly how many doctors have died, after knitting their brows over their own patients; how many astrologers, after predicting the deaths of others, as if death were something important; how many philosophers, after endless deliberation on death or immortality; how many heroes, after the many others they killed; how many tyrants, after using their power over men’s lives with monstrous insolence, as if they themselves were immortal. Think too how many whole cities have ‘died’ — Helice, Pompeii, Herculaneum, innumerable others. Go over now all those you have known yourself, one after the other: one man follows a friend’s funeral and is then laid out himself, then another follows him — and all in a brief space of time.
[tr. Hammond (2006)]

Keep constantly in your mind how many doctors die after a lifetime of wrinkling their brows in thought over the sick; and how many astrologers die after predicting with much ceremony the death of others; and how many philosophers die after exhausting their minds with countless discourses concerning death and immortality; and how many great military men die after killing so many people; and how many tyrants die after exercising their power over the lives of others with an insolent snort, as if they themselves were immortal. And how many entire cities -- Helice, Pompeii, Herculaneum,’ and countless others -- have been destroyed.
[tr. Needleman/Piazza (2008)]

Reflect constantly on how many physicians have died after knitting their brows again and again over the beds of the sick; and how many astrologers after foretelling the deaths of others as though death itself were some great thing; and how many philosophers after endless disputes about death and immortality; and how many heroes after slaying a multitude of others; and how many tyrants after exercising their power over life and death with appalling arrogance, as though they themselves would be immortal; and how many entire cities have, if one may use the word, died: Helice, Pompeii, Herculaneum* and others without number. Also call before your mind, one after another, the many people whom you yourself have known. This man, after paying his last respects to that, was then laid out himself, and the one who laid him out was laid out in his turn, and all in so short a time.
[tr. Hard (2011 ed.)]

Reflect constantly how many doctors have died, after often knitting their brows over those who were ill; and how many astrologers, after predicting the deaths of other people, as if death were some great thing; and how many philosophers, after countless debates about death or immortality; and how many heroes, after killing many other people, and how many tyrants, after exercising the power of life and death with terrible arrogance, as though they were immortal themselves; and how many entire cities died, if one can put it this way, Helike and Pompeii and Herculaneum, and others without number. Run over the ones you know, one after the other: one person attended another's funeral and then was laid out himself, another followed him, and all in so short a time.
[tr. Gill (2013)]