In Chapter 10, why do you think Johnny wanted to keep his gift for Ponyboy a secret from the rest of the Greasers?

it contained a special message for Ponyboy.

Explanation:

Johnny wanted to keep his gift for Ponyboy a secret from the rest of the Greasers because it contained a special message for Ponyboy. The book contained a piece of paper inside it which Johnny had written for Ponyboy.Johnny knew that there was something special inside Ponyboy and he believed that Ponyboy had the potential to bring change in others' lives. He had written the letter to Ponyboy to remind him to stay 'gold' forever and to make an impact in the lives of the people.