A friend is someone who walks into a room when everyone else is walking out
The main character, Gene Moore, is shown how much of his identity is wrapped up in his career and potential in that career. When he comes home from war no longer able to see himself as a baseball prospect, he isn't sure who he is. This is thoroughly reinforced every time one of his acquaintances identifies him by baseball or inquires about his status. How much of our identity and worth is wrapped up in our job title or the one we are aspiring to?