"How did I get so old?"

In Chapter two, Billy travels in time to when he saw his dying mother in a nursing home. She had no life left in her but she mustered up the strength to say "How did I get so old?" (p. 44) This is a question that is asked by most people as they age, even if they are only ten years old. The question everybody has is how did life pass so quickly and leave me here all grown up? We all have a sense of the time traveling that Billy can do. We usually don't realize how fast a moment can pass until it is already gone. To Billy, his life is just moments that pass and go. In one moment, he is a boxcar with a hobo and the next moment he is at a wedding. To us, moments can pass as quickly as Billy's, but just in order.  In the end though, Billy and his mother and everyone else in the world feels the same and worries how they left their lives pass so quickly without a thought.