In Chapter 5, Bud and his mother talk about opening and closing doors. How does this metaphor relate to Bud?

In Chapter 5, Bud explains how his mother used to tell him that no matter how bad things look, when one door closes, another door opens. Her advice about doors closing and opening is a metaphor for Bud's life. Throughout the novel, Bud experiences loss, heartache, and difficulty on his journey to find his father. No matter how bad the situation seemed, Bud was able to make it through the difficult moments, and better opportunities presented themselves. For instance, whenever Bud misses the train outside of the Hooverville, he is forced to hike alongside the road. Coincidentally, the magnanimous Lefty Lewis offers him a ride to Grand Rapids. Bud missing the train is symbolic of one door closing, while Lefty Lewis' ride is symbolic of another door opening.

When Bud arrives at Grand Rapids, Herman E. Calloway initially views him with contempt because Bud claims that Herman is his father. Bud is upset at the fact that Herman is so rude towards him, and denies being his father. At the end of the novel, it is revealed that Herman is actually Bud's grandfather, which means that Bud will stay in Grand Rapids and begin a new chapter in his life. In the last chapter of the novel, Bud is practicing on his alto saxophone, and he comments that the squeaks and squawks were actually the sounds of one door closing and another one opening. Bud learns throughout life that each difficult moment will eventually work itself out for the better, and new opportunities will arise.