story starts with the phrase along the line on how every boy wants to be stronger. story starts with a boy named joe who is physically fragile and sickly, getting physically beat up by other boys,
and how he trains to become stronger. he is selfish and hard to get along with. he works as a boxer and at a circus, where they heckled by cops often. he has a resentment of cops but trains them, and sees that germany is becoming a nazi state. he meets a girl and has a child, but struggles to provide for them because he only makes money if he wins a big match, and they argue a lot. He talks about how he will make it big and be recognized, constantly promising her that he will be successful and change their situation. She wants him to stop boxing. He continues taking on high risk activities, joining a circus, where he watches the performers train animals in the down time. The wife begs him to just take a normal job, after finding how dangerous the circus stunts are. But he is a man driven by adrenaline, and it hurs his pride to put boxing aside and get a regular job. After arguing and failed promises, the couple separate. This is all happening with an upcoming war and political strife in the background. he is selfish, and only focused on making himself stronger. He is not particularly patriotic about germany.
character change happens when he is in prison and realizes he can apply what he learned to make others strong as well. he returns to germany, which is in ruins, to ask his ex wife to come back, but she already moved on. he goes to the US alone, story ends.