Robert Cohn is introduced in chapter one and two as someone who is full of insecurities. He learned to box at Princeton because he was embarrassed about being Jewish; he was so shy he married the first girl that was nice to him. After his marriage breaks up, he is under the spell of a woman named Frances, a woman so jealous that Robert Cohn's one friend can't even talk about women. This is all in the first chapter. Although as a reader you want to hate Cohn for his lack of backbone, as Hemingway lets you in on his history you begin to feel sorry for Cohn. Because of his insecurity he cannot take the lead in any relationship and is constantly following whoever tells him to. In fact, to add insult to injury, one of his few friends, Jake, describes him as "unmanly."
In the second chapter, however, Cohn has a development. After having his book accepted by a publisher in America, he realizes that he is attractive and gains some self confidence, and looses interest in Frances. He has decided, finally, to live life. After the second chapter, Cohn is a little bit in limbo. He knows that he wants to start "living life," but he also has to get away from years of his personality that never allowed him to do so.