Six lines, six full stops, and not a single raised voice. "Infirmitatem" describes an injury large enough to turn the speaker into a river, then calmly reports that nothing hurt. Someone ("you") wounds the speaker with "sharp tears". The speaker bleeds, but feels nothing, because feeling pain is something they are "incapable of." The last two lines turn this report into a riddle: the incapacity is both "my greatest strength" and "my worst weakness." The central idea is that numbness protects and impoverishes at once, because a person who cannot be hurt is also a person who cannot register what is happening to them.
The imagery starts with a deliberate clash. Tears are usually soft, a sign of vulnerability, yet here they are "sharp" enough to stab. The poem never says why "you" is crying, so the tears could be grief, guilt or accusation. What matters is that another person's sorrow becomes a weapon. The next line makes the water imagery run on: tears become blood, and blood becomes "rivers." The scale is striking. A few tears cause a flood, so the damage far outweighs its cause. The poem's one big, dramatic image is also its shortest line, "And I bled rivers", at only five syllables. It is delivered with no exclamation and no elaboration.
The calm of that delivery is where the poem gets its chill. "I did not feel an ounce of pain" borrows the language of weights and measures, as if pain were a commodity that happened to be out of stock. The next line, "For I was incapable of doing so", is the longest in the poem at eleven syllables, and its phrasing is stiff and almost clinical. "Doing so" turns feeling into an action, something one performs or fails to perform. The line sounds like a diagnosis, and the title supports that tone. "Infirmitatem" is Latin for weakness or sickness, in a grammatical form that marks it as the object of a verb. We might read the title as a fragment of a longer sentence, a weakness being acknowledged or carried, though that is an inference. Either way, the title gives away the final word before we begin. The speaker first calls the condition a strength, and only in the last line admits what the title has said all along.
The construction is spare but carefully balanced. There is no rhyme, and the lines are uneven in length, running roughly seven, five, nine, eleven, six and nine syllables. Every line is a complete sentence ending in a full stop, like entries in a report. Yet several of them begin with connecting words: "And", "Yet", "For", "Yet". The grammar keeps reaching for logic (this happened, but that followed, because of this), while the punctuation keeps cutting each thought off. That tension suits a speaker who explains everything and feels nothing. The tenses shift too. The stabbing and bleeding are in the past, but "It is my greatest strength" is in the present, which suggests the numbness is not over. It is a standing condition. Sound reinforces the idea. The hissing s of "stabbed", "sharp" and "tears" gives way to the heavy, almost flat "worst weakness", where the repeated w makes the final phrase sound like a sigh.
What makes the poem worth reading is the doubt it leaves behind. The speaker insists on feeling nothing, yet someone who felt nothing would hardly reach for rivers of blood to describe the event. The imagery suggests that something registered, even if the speaker cannot call it pain. Perhaps that is the real weakness: the hurt happens, but without the ability to feel it there is no way to respond to it, heal from it or even know it is there. The strength is just as real. The speaker survives a stabbing that should have broken them.
Because the poem never decides between the two readings, it avoids the easy moral that numbness is simply bad or simply brave. The repeated "Yet" keeps the two sides in tension, and the poem closes on "weakness", the word the title already named. It ends where it began, and the speaker is still unable to say whether the wound or the armour is the greater loss.