Herodotus, Histories 7.44-46, tr. George Rawlinson:

Having arrived here at Abydos, Xerxes wished to look upon all his host; so as there was a throne of white marble upon a hill near the city, which they of Abydos had prepared beforehand, by the king’s bidding, for his especial use, Xerxes took his seat on it, and, gazing thence upon the shore below, beheld at one view all his land forces and all his ships. While thus employed, he felt a desire to behold a sailing-match among his ships, which accordingly took place, and was won by the Phoenicians of Sidon, much to the joy of Xerxes, who was delighted alike with the race and with his army.

And now, as he looked and saw the whole Hellespont covered with the vessels of his fleet, and all the shore and every plain about Abydos as full as possible of men, Xerxes congratulated himself on his good fortune; but after a little while he wept.

Then Artabanus, the king’s uncle (the same who at the first so freely spake his mind to the king, and advised him not to lead his army against Greece), when he heard that Xerxes was in tears, went to him, and said:-

“How different, sire, is what thou art now doing, from what thou didst a little while ago! Then thou didst congratulate thyself; and now, behold! thou weepest.”

“There came upon me,” replied he, “a sudden pity, when I thought of the shortness of man’s life, and considered that of all this host, so numerous as it is, not one will be alive when a hundred years are gone by.”

Suzanne Steele, www.warpoet.ca

five years ago—was it really five, it feels like five thousand—I shared Xmas dinner with the men in the big hangar. I was a stranger in a strange land seated there between the cooks and the snipers, wide-eyed at a LAV decorated with Xmas fairy lights, and at being served turkey dinner by a WO. I looked around at all those young spirits in uniform, young ones I’d watched muster at Shilo, some for the first time in the field, and wondered to myself, “is it you? is it you? or maybe, me, who will be dead this time next year?” (the latter not probable, but possible, as one of the roads I was supposed to take on a journey while over there, cancelled at the last minute, proved fatal for five a month later). it was, as I looked around me, as if I saw their ghosts. ghosts, while they were still alive.