What was inside the copy of Gone with the Wind that Johnny left for Pony?

Jonny left a note reminding Pony to "stay gold":

I've been thinking about it, and that poem, that guy that wrote it, he meant you're gold when you're a kid, like green. When you're a kid everything's new, dawn. It's just when you get used to everything that it's day. Like the way you dig sunsets, Pony. That's gold. Keep that way, it's a good way to be.