In the poem Tennyson reworks the figure of Ulysses by drawing on the ancient hero of Homer's Odyssey and the medieval hero of Dante's Inferno. Homer's Ulysses is a brave and curious hero,while Dante punishes his curiosity, his desire of knowledge; he punishes him for his hubris because he crossed the Strict of Gibraltar, symbol of the limits of knowledge .Tennyson combines these two accounts by having Ulysses make his speech shortly after returning to Ithaca. However he is a different hero. He is a middle aged man who starts reflecting on his life.
The poem Ulysses is a dramatic monologue. The stylistic choice allows the writer to create a distance between the writer and the speaking voice, and between the speaking voice and the reader. It follows that the reader doesn't feel emotionally involved and he is able to reflect. 
The reflection makes the reader realize that the hero is a Romantic hero indeed he is at the center of the attention. The writer uses verbs of perception ( even making some "mistakes" such as "know not me", "much have I seen", "I am become",...) instead of verbs of action in order to put in result the essence of the human being instead of his "savage race". There is also one more element that focuses the attention on Ulysses: the presence of the personal “I” ( “I cannot”, “I will”, “not me”,…). As a result the reader will know a lot about the character and his personality through what he says. 
Indeed language reveals a lot about Ulysses and his attitude towards the world. Right from the start the intelligent reader will notice the speaking voice's opinion on contemporary society: "unequal laws", "savage race", "hoard, and sleep, and feed", "rugged people". The combination of these words and verbs provides a negative connotation of a society strongly attached to material goods that doesn't recognize the real values anymore. 
On the other side though there are Ulysses’ "friends" those who travelled with him. Frequently in the poem the speaking voice refers to them: "those that loved me", "them all", "my peers", “Souls that have toil'd, and wrought, and thought with me". These references to "others" underline the importance of somebody else in Ulysses’ life.
In addition Ulysses is a man who has never lost a second of his life. In the first part of the poem he asserts: "I will drink life to the lees: All time I have enjoy'd greatly, have suffer'd greatly". He has always been pushed by the desire of knowing and travelling. And it is thanks to travels that he discovered who he is: “I am a part of all I have met". 
What is really interesting and almost disorienting is Ulysses’ attitude towards life. He is not a teenager anymore but at the same time he looks at what remains, those hours as what "is saved from the eternal silence". He does not give up. Death brings everything away ("Death close all") and the human being has no power against it. But there is always "a bringer of new things". 
In conclusion, the intelligent reader will realize that Tennyson's poem marks an important passage between Romanticism and Modernism. Ulysses is a romantic hero but his voyages, his relationships, his thirst of knowledge, will let him to a deeper reflection on himself. This passage underlines the first step from the romantic subjectivity to the modernist one.