Christopher finds people confusing because they use body language that he doesn’t naturally understand the way other people do, and because people use many metaphors in speech. A metaphor, he explains, is when a person describes something with a word other than what the thing actually is. This, he thinks, is really a lie, and besides, the metaphors don’t make any sense when he imagines them literally.
Christopher’s own name is a metaphor that means “carrying Christ,” because St. Christopher carried Christ across a river. However, this story is also a lie. Christopher’s mother liked this story because it was about kindness, but Christopher doesn’t want his name to mean anything beyond himself.
Christopher’s desire for truth keeps him from appreciating the value of symbolic stories. Christopher’s mother is mentioned here for the first time, only in passing because her absence is so normal to Christopher that he doesn’t see the need to explain it yet.