What does Armpit realize about a song he hears Kaira sing?

Kaira refers to her life being unpredictable. The narrator comments that the stains are still on Armpit's sweatshirt. As the song finishes, Armpit realizes that Kaira may not be singing to him as much as about him. He hopes that he might see her again, but he thinks he'll be all right if he doesn't. He's got his own small steps to take.