When sitting by his campfire and getting lost in his thoughts, Nick reflects on his relationship with his friend Hopkins, alluding to World War I in the process:
Hopkins went away when the telegram came. That was on the Black River. It took eight days for the telegram to reach him. Hopkins gave away his .22 caliber Colt automatic pistol to Nick. He gave his camera to Bill. It was to remember him always by. They were all going fishing again next summer […] He was excited but serious. They said good-bye and all felt bad. It broke up the trip. They never saw Hopkins again […]
His mind was starting to work. He knew he could choke it because he was tired enough.
When the narrator describes how Hopkins “went away when the telegram came,” they are alluding to the telegrams American men would receive that said they had been drafted to serve in World War I. That Hopkins gave away his belongings to his friends as a way for them to “remember him always” suggests that he was aware of the possibility of dying in action. This does, in fact, seem to be what happens—as the narrator says, “They never saw Hopkins again.”
It is notable that, while thinking of this, Nick’s “mind was starting to work,” seemingly meaning that he was starting to tap into painful memories and feelings. Nick clearly does not want this, preferring to “choke” his mind and go to sleep rather than face the various traumas he experienced during the war. Clearly, Nick uses a form of self-control to keep himself emotionally stable, using fatigue (and physical discomfort) to override his emotional pain.
