Nine short lines, and the whole drama sits in the last three. "I'm Sorry, Sir" is a poem about wanting someone who is busy wanting someone else, and about the small, painful power of saying no to him politely. Nothing is known here about who wrote it beyond the username Little_Mystery, so the poem has to speak for itself. Its reticence suits that name.
The opening couplet states the problem plainly: "I can't get you out of my head when I know I should, / They say I should forget you but only If I could." The speaker is caught between what she knows and what she feels. The vague "They say" brings in an unnamed chorus of friends or common sense, all offering advice she can't use. The couplet's lines are the longest in the poem, and their length feels like rambling, the way a thought loops when it won't let go. The capital "I" in "only If I could" may be a slip of typing, but it falls on the hinge of the conditional, and it makes the admission of helplessness a little louder.
Then the lines shrink and the rhymes come quickly. "You're always on my mind, / Even when you're un-kind." The hyphen in "un-kind" is the most interesting detail in the poem. It splits the word so that "kind" stands alone for a moment before the "un-" cancels it, as if the speaker keeps glimpsing the person she hopes he is before the unkindness takes it back. It also shows how much she excuses: his unkindness gets only half a line, tucked inside a rhyme that makes it sound almost sweet.
The poem is built on three pronouns. "You" dominates, "I" is nearly absent, and "She" arrives in the fifth line: "She's all that you think about, / But you still have a doubt." The rival is never named and has no other detail, which makes her more powerful. She exists only as the thing he thinks about. The word "about" appears twice, first describing his obsession and then in the next couplet, "You asked me for advice about her." The repetition links his fixation to the favour he asks, so the speaker is made to serve the very feeling that excludes her. "Still have a doubt" also carries a faint, unspoken hope, since doubt is the one gap through which she might fit.
The rhyme scheme holds until the very end. Four couplets chime neatly: should/could, mind/un-kind, about/doubt, her/Sir. The ninth line, "I can't help you there," has no partner. Having rhymed "her" with "Sir" (the title word, formal and distancing), the poem leaves its final line hanging. That is the refusal in sound form: the pattern stops where her help stops. The lines also get shorter as they go, from the long opening couplet to the five syllables each of "But I'm sorry, Sir" and "I can't help you there." The poem ends in clipped, almost businesslike phrases, as though she is shutting a door while keeping her composure.
That formal "Sir" is the poem's central choice, and it is ambiguous. Judging by the text, it could be the language of someone who has to keep her distance, or a defence she puts up because the intimate "you" of the opening has been too exposed. The apology works two ways as well. "I'm sorry" is regret, but it is also the ordinary phrase for turning down a request, and the speaker lets the politeness cover up what the refusal costs her. She never says why she can't help. The poem implies it, and the reader can fill in the reason.
What makes the poem worth reading is that it treats restraint as an action. Nobody storms off or confesses. The speaker simply declines to become the advisor in someone else's love story, and that quiet refusal protects her. The poem is small and its rhymes are simple, but it understands that the hardest thing in a one-sided attachment can be to say very little and stop.