In the note to Pony Johnny makes a reference to a Robert Frost poem. This reference is important because he is pointing out to Pony that he still holds on to the innocence from his childhood and he does not want Pony to lose that. He also stated that Pony doesn't have to be a greaser forever. This is significant because it changes Pony's outlook on his future. Often people feel like their destiny or future is laid out for them. Especially if we grew up without the best of circumstances. Johnny wanted Pony to know that he wasn't destined to be a greaser forever, even if that is all he knew. He wanted Pony to know that he had the ability to change his future. So in short, appreciate the innocence in life and go for what you want. Don't stay within the confined lines that you were raised in.