"Miscalculation" turns an old piece of folk wisdom inside out. To "rob Peter to pay Paul" means to settle one obligation by creating another, shifting a loss from one person to someone else. It is a proverb about financial desperation and its shabby arithmetic. Kay Sage borrows it and then lets the logic fall apart in her own hands. The speaker has done the robbing, but the transaction is meaningless on both ends: Peter "has simply / missed / nothing at all," and Paul "does not / really / want / to be paid." The theft produced no victim and no beneficiary. Whatever the speaker thought she was fixing was never broken in the way she believed.
The poem's central idea is that effort can be misdirected so completely that it loses its point. The speaker calls her mistake "a tactical error," a phrase borrowed from the language of strategy, and the coolness of it is part of the humor. She sounds like a general reviewing a failed campaign. But the error she names is not that she was caught or that the plan went wrong. It is that nobody involved cared. The wounding discovery is indifference. Peter is not hurt by the loss, and Paul is not helped by the payment. The speaker has acted on an assumption about what other people need, and the assumption was simply wrong.
Read more broadly, the poem can be taken as a small parable about emotional bookkeeping. The judging by the language alone, the debts here could be money, but they could just as easily be attention, apology, or affection. Many of us keep silent ledgers of what we owe and are owed, and sometimes we sacrifice one relationship to repay another, only to learn that neither party was keeping the same account. The poem never says which reading is correct, and that openness is a strength.
The construction does a great deal of the work. The poem has no rhyme and no regular meter, and it relies instead on line breaks to control timing. The first four lines run in a fairly normal, conversational rhythm, rolling forward with the proverb. Then the lines begin to shrink. "For Peter / has simply / missed / nothing at all" breaks a short sentence into fragments, and each break forces a pause before the punchline. The word "missed" sits alone on its line, so that for a beat we might read it as the speaker missing something, or Peter missing his money, before "nothing at all" arrives to cancel the idea. Sage uses the page itself as comic timing.
The ending is where this technique pays off. "And Paul / does not / really / want / to be paid" is stretched across five lines, nearly one word each, so that the poem slows almost to a halt. The isolated "really" is the most interesting word in it. It is a softener, the kind of hedge a polite person uses to avoid saying something blunt. Paul does not "really" want to be paid: the word suggests a faint, awkward reluctance rather than a flat refusal, as though the speaker is describing a social moment in which her generosity is being gently declined. The slowing rhythm mimics that hesitation. We can almost hear the pause before the bad news.
The tone throughout is dry and self-mocking. Nothing in the poem is dramatic: there is no exclamation, no complaint, no metaphor beyond the borrowed proverb. The restraint is the point. A failure this complete does not need decoration, and the understatement makes the little disaster funnier and more believable. The title reinforces this by naming the whole situation in one clinical word, a miscalculation, as if feeling had been reduced to a sum that did not add up.
What makes the poem worth reading is its economy. In under thirty words of real content, it takes a cliché, exposes the assumption hiding inside it, and leaves us with a small, recognizable humiliation: working hard to solve a problem that was never there.