Telemachos is the son of Odysseus and Penelope. He is marked by his prudence and, as we are told time and again, his clear-headedness. This guy is not one to rush into action without first considering the consequences. That said, he is getting impatient with all these suitors, who are wasting his family’s riches, treating him badly, and trying to snag (and snog) his mother. What this means is that we pick up the action at the most exciting part – when Telemachos is finally about to do something about it.
It’s notable that it takes a good deal of coaxing from Athene to goad Telemachos into action. The young man repeatedly refers to the fact that the suitors are older, stronger, more experienced, and likely better fighters than he is. (This makes sense; Penelope at one point references him growing a beard for the first time, so he’s just maturing when the story starts.) One major theme in the Odyssey, therefore, is Telemachos’s physical, emotional, and spiritual growth.
Part of the way we trace this growth is by watching Telemachos’s interactions with his mother. One way he asserts his adult status is by telling her what to do – thereby taking control of their relationship. Penelope, far from being bothered, encourages this behavior, clearly glad to see her son stepping up to his role. Another is when he leaves on his journey without telling her in advance. (Penelope is less pleased about this.)
All the same, it’s a lot easier to stand up to his mother than it is to give the suitors what’s coming to them. After all, even public speaking gives this guy the shakes. This is one reason why Telemachos is so eager to find his father – for help. When Odysseus comes, Telemachos suddenly gains confidence – notice how he insults the suitors more and more freely? Suddenly, he is able to fight, even despite his lack of combat experience. Not that he’s an expert. When he screws up by forgetting to close the door to the room where he’s hid the suitors’ weapons, we can see that he still has a lot to learn.
That said, the poem gives us confidence that we will get there. A lot of this has to do with genetics; after all, he is Odysseus’s son. Telemachos’s ability to string the bow (Homer says he was about to do it before Odysseus gave him the signal to knock it off) is certainly a mark of his innate (and likely inherited) strength. Again, because of his paternity, Telemachos is sheltered and protected by Athene – Odysseus’s own private support system and powerful lucky charm. It is appropriate, then, that in the retribution scene we see Telemachos side-by-side with his father and grandfather, dispensing justice as one, united front.