Darry and I would probably still have misunderstandings – we were too different not to – but no more fights. We couldn't do anything to hurt Soda. (12.57)
Interesting how not fighting becomes a gesture of great love. By finally telling his brothers how he feels, they're also able to show their love for each other.
There's still a lot of good in the world. Tell Dally. I don't think he knows. Your buddy, Johnny. (12.64)
In his deathbed letter, Johnny sends Pony a message of love and hope, and wants him to spread it around. That's a big motivation for Pony to put pen to paper and write his story.