Today, many people are familiar with Post-Traumatic Stress Disorder (PTSD), a condition of sustained mental distress caused by traumatic experiences. Military personnel are particularly prone to this disorder because of their combat experiences. Currently, PTSD is treatable through methods like cognitive behavioral therapy and medication. However, in Charley’s day, no formal diagnosis, understanding, or treatment options existed for soldiers suffering from what was then termed “Soldier’s Heart.” The existence of such a term implies that people recognized the mental anguish some men experienced after returning from war. Despite this, scientific and medical knowledge was limited; doctors did not have the awareness to diagnose the disorder much less help the men suffering from it.

Even though PTSD did not exist as a medical diagnosis, many soldiers suffered from it. Paulsen uses Charley’s character as an example of one man who entered battle at a tender age without much preparation either mentally or physically, and emerged with mental and emotional scars. Through the progression of battles in the novel, Paulsen shows how combat changed Charley’s character and personality. At first, Charley is friendly and open with the soldiers in his unit, but when many are lost in battles, he withdraws, finding it easier to be alone than to make friends that will inevitably die.