One thing it took me a while to appreciate in the LOTR films were the parallels between Frodo and Boromir—
At the end of Fellowship of the Ring, the two of them are both planning to “break the fellowship” for their own reasons.
Frodo wants to protect the others from the corruption of the Ring. Boromir wants “the strength to protect his people.” Both would have to sacrifice the fellowship for this— “to bear a ring of power is to be alone.”
They convince themselves it is their duty to save the world on their own: that this is their quest and their burden, and that they must take it even if it they do it alone, against the will of the rest of the Fellowship.
Boromir tells Frodo “I know why you seek solitude. You suffer— I see it day by day.” Earlier in Lothlorien, Boromir had walked away from the group to grieve alone.
When Boromir is first introduced, he has a large flashing arrow over his head saying “this man is going to be corrupted by the power of the Ring.” The other characters are often mistrustful of him, deeply wary, or treat his corruption as an inevitability. Gandalf warns Frodo about how “evil will be drawn to you from outside the Fellowship and, I fear, from within” while casting a side-glance in Boromir’s direction.
When the Fellowship is refused entry to Lothlorien because of the One Ring, there’s a scene where the other members of the Fellowship can’t meet Frodo’s eyes, looking away whenever he looks at them— it’s as if they’re starting to perceive him as the burden, and not the Ring.
Boromir notices this, and tells Frodo “you carry a heavy burden; don’t carry the weight of the dead.” He does not take his own advice: he carries the weight of Gondor’s dead. Fighting on the front lines of the battle between Gondor and Mordor has left him with far less hope than the other characters; he acts resentful of the other characters, because he believes they don’t truly understand the threat Mordor represents, because they haven’t spent the past few years on the front lines like he has. He tearfully confesses his kingdom “looks to him to make things right and [he] would do it”— it his duty to singlehandedly save Minas Tirith. The weight of this burden is what makes him so susceptible to the power of the Ring— which, in turn, is what makes everyone else so wary of him.
By carrying these burdens, Frodo is also becoming isolated from the other members of the Fellowship, the way that Boromir is.
At night on the banks of the Anduin, Frodo/Sam and Aragorn/Boromir have arguments that parallel each other— Sam tries to help Frodo and Frodo pushes him away; Boromir urges Aragorn to go to Minas Tirith and Aragorn pushes him away.
After the climactic battle at Amon Hen, they’re both in despair— Boromir believes his death means the end of the kingdom that has been relying so heavily on him, Frodo believes he is doomed to travel to Mordor on his own. But both are are ultimately “saved.” Aragorn swears to defend the people of Gondor, who he accepts as his people, and Sam refuses to let Frodo leave alone.
The parallels continue in the next films as well though: Frodo is ultimately corrupted by the Ring, just as Boromir was; he’s crushed under the weight of the burden he took on. But it’s just fascinating to see how much they have in common, despite being so different on the surface.
