Why is pony boy so reluctant to tell Darry how he really feels after the incident with the Socs?

After the gang chases away the Socs, Darry starts scolding Ponyboy for walking home from the movies by himself, and Ponyboy explains to the reader that "Me and Darry just didn't dig each other. I never could please him." Ponyboy doesn't feel that he can talk to his brother because he feels as if he can't do anything right.