"This way people have of lining-up on the side of the undertaker makes the entire pharmacopeia look silly. Your little lady has made up her mind that she's not going to get well."
At the beginning of the story, the doctor concludes that Johnsy has lost her will to live. He laments how often patients line up on the side of the undertaker, by which he means that Johnsy, like many patients, give up hope of survival, thereby reducing the effectiveness of any medical intervention. He suggests that a patient's recovery depends on their attitude toward their illness and belief in their own chances of survival. This passage is significant because it proves true: because Johnsy decides not to die until she sees the last leaf fall, she ends up surviving, having been tricked by the painted leaf.
"I want to see the last one fall. I'm tired of waiting. I'm tired of thinking. I want to turn loose my hold on everything, and go sailing down, down, just like one of those poor, tired leaves."
In this passage, Johnsy reiterates her belief that her fate is connected to the last leaf on the ivy vine outside her window; she imagines the satisfying reprieve from her illness that death will bring. As the leaf clings to the vine, she believes she has a tenuous and painful hold on life. She wishes to give up and sail away, her spirit relieved of suffering like a leaf swept off on the breeze.
The lonesomest thing in all the world is a soul when it is making ready to go on its mysterious, far journey. The fancy seemed to possess her more strongly as one by one the ties that bound her to friendship and to earth were loosed.
Though Sue and Johnsy are close friends, Johnsy reject's Sue's affection during her illness. The pain of living with pneumonia makes Johnsy close herself off from other people; she has made up her mind to die, and so finds Sue's requests that she drink broth irritating. The narrator comments in this passage on the lonesome state Johnsy is in, where she is in a way preparing herself for death by ignoring her bonds to other living beings.
An artist once discovered a valuable possibility in this street. Suppose a collector with a bill for paints, paper and canvas should, in traversing this route, suddenly meet himself coming back, without a cent having been paid on account!
In the story's opening paragraph, the narrator describes the winding streets of Greenwich Village and provides an anecdote about how a bill collector might get turned around in the confusing maze. This anecdote establishes the ironic quality of O. Henry's narrative, and foreshadows the ironic reversal of expectations that is to come at the story's end.
"Didn't you wonder why it never fluttered or moved when the wind blew? Ah, darling, it's Behrman's masterpiece—he painted it there the night that the last leaf fell."
The story's final lines reveal the ironic twist that led to Johnsy's survival and Behrman's death: what Johnsy believed was a final living ivy leaf was in fact a painting of a leaf that Behrman applied to the wall during a storm, all of which resulted in him contracting and dying from pneumonia. Though the outcome is bleak in most respects, Sue chooses to view Behrman's sacrificial artistic intervention as the great masterpiece he had always intended to create. In this way, the story ends on an ambiguously hopeful note, as Behrman proved to be a talented painter by the end, freed from his identity as a failure.
