What signs are there that Auggie is growing up when he prepares to get ready for camp?

Auggie asks his Mom to buy him a new duffel bag, because the old one has Star Wars designs. He wants to try to shake off his Star Wars image, because in middle school you can be strongly defined by such hobbies. Mom helps him pack; Auggie wants to bring Baboo, his stuffed bear, for comfort. In the morning before he leaves, however, he changes his mind and removes Baboo from his bag, leaving the bear on his bed with a note to Mom. The note says that, if Mom misses him, she can cuddle with Baboo herself.