The poem is short and a little puzzling at first, because the speaker never says who "they" are. The clues suggest a close relationship, perhaps with family or loved ones, though the poem leaves that open. What comes through clearly is how much the speaker values them: "I have no greater possession." The word "possession" is interesting, since it sounds like something owned, yet the feeling behind it is tender.
Then the tone shifts. The same people can also be "a weapon," and the list that follows, "arguments / hormones / eruption," reads like a quick sketch of a household losing its temper. The short, clipped lines make the outbursts feel sudden.
The ending is the most telling part. "Things happen / it is what it is" sounds calm, but it may also be tired. The speaker seems to accept the conflict because the love underneath is stronger. The mood is affectionate, worn, and quietly resigned.