"Don't judge a book by its cover."
Holden is always the one being judged. Since he is gay people say that he's also nasty and that you can't be friends with a gay guy. These are all just stereotypes, when you get to know Holden, he is a loving and caring person, just like everybody else. So what if he's gay, it shouldn't matter who you like. All that should matter is his personality. He's just like everybody else but nobody realizes that.
"Appreciate what you have; you never know when it might be gone."
Fern doesn't realize how much she has until somethings gone. She finally realizes this when it's too late and she can't take anything back. No matter how much she wishes she could. She was mean and showed bad examples but now she wishes she would have acted different and been nicer. Most of all she wished she would have appreciated what she had a lot more.