A quiet confession of self-doubt, "not enough" opens with a feeling the speaker says is constant: they always seem to fall short for other people. The words are plain and the lines are short, which makes the admission sound unguarded, almost like someone saying it out loud for the first time.
The second stanza is where it gets heavier. The speaker doesn't just feel inadequate, they say they agree with that judgment "most of the time." The last lines go further. Someone could say it to their face and the speaker might not even push back. That isn't anger or self-pity so much as tired resignation, as if arguing has stopped feeling worthwhile. The mood is bare, sad, and a little vulnerable. There's also a hint of quiet invitation, or challenge, in the dash: the speaker seems to expect rejection, and has braced for it so long that they've stopped defending themselves.