August explains that he's aware that he's not an ordinary kid. He does normal things like eat ice cream and play his Xbox, but he knows that normal kids don't make other kids run away screaming. He says that if he had one wish, he'd wish for a normal face. August thinks that the only reason he isn't truly ordinary is because nobody else sees him as ordinary.
The way that August talks about his identity, even at this early point, shows that there are two facets to his sense of self: his inner identity (feeling normal) and his outward-facing identity (his face, which is all other people see).
However, August says that he's used to the stares, as are Mom and Dad. His big sister, Via, isn't good at pretending—she often gets really mad and even yells at kids. Mom, Dad, and Via don't see August as ordinary, as they see him as both extraordinary and in need of protection. August insists he's the only one who believes he's ordinary. He formally introduces himself to the reader and declines to describe what he looks like. He says that whatever the reader thinks he looks like, the truth is probably worse.
Via's reaction to those who tease August suggests that even though she's also just a kid (the novel later reveals that she's about fifteen), in a lot of ways she takes on an almost parental role for August. This shows that Via has grown up much faster than other kids and possibly hasn't had the opportunity to truly be a child, something that she'll confirm later.