The mood, like the tone of the story, varies greatly depending on the narrator's mentality and current thought. At times, the narrator's speculation creates a very nihilistic, or pessimistic, mood:
Oh! dear me, the mystery of life; The inaccuracy of thought! The ignorance of humanity!
In other sections, the narrator's outlook is more positive, and the mood becomes hopeful:
Still, there's no harm in putting a full stop to one's disagreeable thoughts by looking at a mark on the wall. Indeed, now that I have fixed my eyes upon it, I feel that I have grasped a plank in the sea.
In times of uncertainty or social and political upheaval, emotions often run high, with individuals vacillating between hope and despair, between optimism and nihilism. Aside from conveying realistic changes in temperament that occur naturally as a person moves from thought to thought, Woolf's widely variable mood in "The Mark on the Wall" conveys to the reader that the narrator is living through difficult, uncertain times. This is indeed true of the 1920s: in addition to being a tumultuous post-war period, this particular decade saw a great deal of social, political, and economic upheaval. Both the narrator and Woolf must grapple with the complex issues of their time - hence this story's variable "mood swings."