When I began reading this poem by Tennyson, it was so difficult that I nearly passed it by; but being prompted by curiosity and experience which has taught me I'll have to squeeze hard to get the nectar, I read and re-read it until I began to understand it. 

Initially what inspired me was the last half where Ulysses, the aging warrior, begins to reject thoughts that he is too old. And catches sight of the port and ships sails puffing in the wind and believes, “Some work of noble note, may yet be done,”
 He rallies his courage and assesses himself to find, “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.” Or as the lyrics in the Sara Groves song, “We are what we are and it is more than enough.”

As I too, find myself aging, I hope I will rally my courage “To strive, to seek, to find, and not to yield.” 

Here is the complete poem and I included someone’s summary at the end.

“Ulysses”

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.

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, and when
Thro’ scudding drifts the rainy Hyades
Vext the dim sea: I am become a name;
For always roaming with a hungry heart
Much have I seen and known; cities of men
And manners, climates, councils, governments,
Myself not least, but honour’d of them all;
And drunk delight of battle with my peers,
Far on the ringing plains of windy Troy.
I am a part of all that I have met;
Yet all experience is an arch wherethro’
Gleams that untravell’d world whose margin fades
For ever and forever when I move.
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! Life piled on life
Were all too little, and of one to me
Little remains: but every hour is saved
From that eternal silence, something more,
A bringer of new things; and vile it were
For some three suns to store and hoard myself,
And this gray spirit yearning in desire
To follow knowledge like a sinking star,
Beyond the utmost bound of human thought.

   This is my son, mine own Telemachus,
To whom I leave the sceptre and the isle,—
Well-loved of me, discerning to fulfil
This labour, by slow prudence to make mild
A rugged people, and thro’ soft degrees
Subdue them to the useful and the good.
Most blameless is he, centred in the sphere
Of common duties, decent not to fail
In offices of tenderness, and pay
Meet adoration to my household gods,
When I am gone. He works his work, I mine.

   There lies the port; the vessel puffs her sail:
There gloom the dark, broad seas. My mariners,
Souls that have toil’d, and wrought, and thought with me—
That ever with a frolic welcome took
The thunder and the sunshine, and opposed
Free hearts, free foreheads—you and I are old;
Old age hath yet his honour and his toil;
Death closes all: but something ere the end,
Some work of noble note, may yet be done,
Not unbecoming men that strove with Gods.
The lights begin to twinkle from the rocks:
The long day wanes: the slow moon climbs: the deep
Moans round with many voices. Come, my friends,
’Tis 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. 

Alfred Lord Tennyson

Summary

Ulysses (Odysseus) declares that there is little point in his staying home “by this still hearth” with his old wife, doling out rewards and punishments for the unnamed masses who live in his kingdom.

Still speaking to himself he proclaims that he “cannot rest from travel” but feels compelled to live to the fullest and swallow every last drop of life. He has enjoyed all his experiences as a sailor who travels the seas, and he considers himself a symbol for everyone who wanders and roams the earth. His travels have exposed him to many different types of people and ways of living. They have also exposed him to the “delight of battle” while fighting the Trojan War with his men. Ulysses declares that his travels and encounters have shaped who he is: “I am a part of all that I have met,” he asserts. And it is only when he is traveling that the “margin” of the globe that he has not yet traversed shrink and fade, and cease to goad him.

Ulysses declares that it is boring to stay in one place, and that to remain stationary is to rust rather than to shine; to stay in one place is to pretend that all there is to life is the simple act of breathing, whereas he knows that in fact life contains much novelty, and he longs to encounter this. His spirit yearns constantly for new experiences that will broaden his horizons; he wishes “to follow knowledge like a sinking star” and forever grow in wisdom and in learning.

Ulysses now speaks to an unidentified audience concerning his son Telemachus, who will act as his successor while the great hero resumes his travels: he says, “This is my son, mine own Telemachus, to whom I leave the scepter and the isle.” He speaks highly but also patronizingly of his son’s capabilities as a ruler, praising his prudence, dedication, and devotion to the gods. Telemachus will do his work of governing the island while Ulysses will do his work of traveling the seas: “He works his work, I mine.”

In the final stanza, Ulysses addresses the mariners with whom he has worked, traveled, and weathered life’s storms over many years. He declares that although he and they are old, they still have the potential to do something noble and honorable before “the long day wanes.” He encourages them to make use of their old age because “ ’tis not too late to seek a newer world.” He declares that his goal is to sail onward “beyond the sunset” until his death. Perhaps, he suggests, they may even reach the “Happy Isles,” or the paradise of perpetual summer described in Greek mythology where great heroes like the warrior Achilles were believed to have been taken after their deaths. Although Ulysses and his mariners are not as strong as they were in youth, they are “strong in will” and are sustained by their resolve to push onward relentlessly: “To strive, to seek, to find, and not to yield.”