What citation in the book and WHY, would describe the theme coming of age?

Frenchie is frustrated. He is really still just an adolescent trying to come to terms with his life.

"We're all dead anyway. I should make a shish kebab of your kids."

I didn't mean it. I looked at their round eyes, wet and watching but not nervous enough for the threat of a human. Their dad was there, after all, and they knew they were safe. I felt tears collecting behind my own eyes like sand in a windstorm. I opened my mouth...to say what? To apologize to a group of wild guinea pigs? To explain that I hadn't meant what I'd said? To let them know I just missed my family?