Maybe that's all we'll ever be: that is the thought the speaker can't shake. The poem is a short, quiet admission that a relationship, or perhaps a connection between two people, has stalled before it ever became whole. The speaker compares it to an incomplete sentence and a half-written story, two images of something that started with promise but never got where it was going.
The twist comes in the last two lines. "Finished" sits alone on its own line, a blunt word after all the talk of things left incomplete. So the story is not simply unfinished; it is over, and it has no happy ending. That small contradiction is what makes the poem sting. The word "maybe" softens the opening, as if the speaker is still testing the idea and hoping to be wrong, but the ending sounds more resigned.
The mood is wistful and sad, with a kind of tired acceptance. The trailing dots after each image feel like trailing thoughts, as though the speaker's voice keeps fading out.