Bobby didn't know what it meant until he tore up Feather's adoption papers. Frank had died after Feather was born, Bobby said he swore he saw him. This symbolizes the realization that he became a man by taking responsibility for his daughter, even though she was only sixteen. Another key thing to remember is that he gave up his childhood. In the book he took his basketball and placed it on the sidewalk and, on its own, it rolled away, symbolizing his childhood leaving him. It also symbolizes that he is taking responsibility for her and is no longer dependent on his mother so much. He once noticed that he had lost something and later realized that he had lost his old self. The change also affected the way Bobby grew up because at first Nia and Bobby were going to give Feather away to another family, but after Nia became brain dead she decided she didn't want to lose anyone else. When someone leaves a person's life, they lose all the time they had and all the time they could have had. It was hard for Bobby too because he knew she had Feather and she looked so much like Nia that the pain of losing her hit him harder than ever, but it didn't stop him from taking care of her.