The speaker starts out sounding almost philosophical, as if sketching a small theory of how people and writing blur together. Some people turn into poetry, others into prose, and then the idea flips: poetry and prose can turn into people. Writing and living seem to feed into each other, with no clear line between them.
Then the poem narrows sharply. After gathering up all of that, every poem, every sentence, every person, the speaker points to one individual and says, "You are my favorite." The plain, simple ending lands harder because of the grand setup before it. It's a love note that takes the long way around.
The mood is warm, a little playful, and sincere. The short lines and quiet confidence make it feel like something said softly to one person, with the whole world of words offered up just to show how much that person stands out.