A teenager faces a college essay prompt asking what they'd change about their life in five years. Usually they write safe, cookie-cutter answers that hide what they really feel. This time, trusting that strangers who will never know them can't hurt them, they tell the truth. But the essay comes back, apparently sent on to the speaker's mother in the mail with a letter of congratulations, and the speaker spends the night "bruised and scolded."
The mood is quiet, bitter, and a little resigned. The speaker feels exposed and betrayed, since the anonymity they counted on didn't hold. The lesson they're handed is that feelings belong buried, and the long image of a box in a safe behind a locked door with cobwebs shows how extreme that burying is: so deep that you can't even recognize your own emotions. The short final line, "not put to paper," lands like a rule the speaker has now been taught, and it's ironic, because the poem itself is exactly that: feelings put to paper.