Ulysses, by Tennyson -- a classic poem of the aging hero. The full text may be found here. Tennyson begins the poem:
It little profits that an idle king,
by this still hearth, among these barren crags,
match'd with an aged wife,
I mete and dole unequal laws unto a savage race,
that hoard, and sleep, and feed, and know not me.
expressing, his sense of disconnection, being last among his generation, friends all dead; his age, via reference to his once legendarily desired wife; his idle (purposeless) existence; and the mundane world he is now hopelessly entangled in.
I cannot rest from travel: I will drink life to the lees:
all times I have enjoy'd greatly, have suffer'd greatly,
both with those that loved me, and alone, on shore,
Referencing his most famous of stories, great not only for his exploits but because of his legendary suffering, being the lone survivor. He speaks of his raging against the dying of the light in his restlessness and thirst for life, and recalls how he
drunk delight of battle with my peers,
far on the ringing plains of windy Troy.
and notes:
How dull it is to pause, to make an end,
to rust unburnish'd, not to shine in use!
as tho' to breathe were life!
He goes on to talk about handing his kingdom down to his son, of his lost companions from his famous journey, all lost beneath the gloomy seas, protesting that
Death closes all: but something ere the end,
some work of noble note, may yet be done,
not unbecoming men that strove with Gods.
And, ever defiant, Ulysses concludes:
'T is not too late to seek a newer world.
Push off, and sitting well in order smite
The sounding furrows; for my purpose holds
To sail beyond the sunset, and the baths
Of all the western stars, until I die.
It may be that the gulfs will wash us down:
It may be we shall touch the Happy Isles,
And see the great Achilles, whom we knew.
Tho' much is taken, much abides; and tho'
We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.