Dr Rivers' Empathy
Dr Rivers has lost the ability to visualize anything and can only access memories as facts, but not visualize them. Ironically, the ability to visualize things intensely is the thing that he has the most empathy for in his patients. Assuming that a trauma took away his ability to visualize, protecting his mind from what it might find, he is overly-empathetic for those who are plagued by these visualizations as they seem to be the cause of many of their more serious emotional disorders.
Beattie's William
Beattie Roper is beside herself with worry over the welfare of her son, William, who as a conscientious objector is being held in a cold cell, naked. She expects Billy Prior to be worried about William too, and outraged by his treatment, but ironically Prior is the one person who will not feel any sympathy or concern for William as he lost three of the men in his unit to frostbite whilst they were serving their country, and is therefore the last person who would sympathise with someone who is indoors and only feeling cold because he is refusing to serve as these deceased soldiers did.
Women in the War
One of the suffragettes who is now driving a war vehicle around London and participating actively in the war on the home front states that "for women, this is the first day in the history of the world". This is ironic because for most of the men it is the end of the world. For women, who have traditionally been confined to home-making roles, or minor roles, whether they liked it or not, this new active involvement in the war is broadening their horizons and giving them opportunities that they otherwise would not have, and now that the genie of women's partial liberation has been let out of the bottle it is going to be very difficult for it to be put back in again, so whilst most of the world feels as if it is ending, for women, it feels like opportunities are opening up in front of them.
No Hope Street
There is a street in the neighborhood in which Billy Prior grew up called Hope Street. Its name is incredibly ironic, since the locals have nicknamed it "no hope street" due to the number of people committing suicide in the area. A further irony is that since the outbreak of the war there have been fewer suicides, Prior noting that the war seems to have cheered everyone up.
Billy's Father
Billy Prior's father is dedicated to raising the status of the working classes and will use every opportunity presented by the war to effect this change. Ironically, his love of the working classes does not extend to working class women whom he continues to make sure stay as oppresssed and as powerless as possible, seeming to campaign harder for women to be prohibited from voting under the age of thirty than he does for the rise of the working man.