The complex relationship between Ponyboy and Darry is initially explored in the first chapter of this classic work of fiction, when Ponyboy tells us how he feels that he loves Sodapops more than anyone else, including his brother Darry. Note what he tells us about his relation with his elder brother:
[Soda's] always happy-go-lucky and grinning, while Darry's hard and firm and rarely grins at all. But then, Darry's gone through a lot in his twenty years, grown up too fast.
We are in addition told that Darry works "too long and hard" as he has been left, as the eldest brother, to look after Sodapops and especially Ponyboy. However, it is clear that in spite of the way that Ponyboy appreciates and understands something of the sacrifices that Darry has had to make to look after them, he also is annoyed by the way that Darry is always "hollering" at him and treats him as if he were "six instead of fourteen." It is only in the final chapter, after Sodapops forces the brothers to become reconciled to each other, that Ponyboy realises that he does love Darry and that Darry loves him:
I suddenly realised that Darry was only twenty, that he wasn't so much older that he couldn't feel scared or hurt and as lost as the rest of us. I saw that I had expected Darry to do all the understanding without even trying to understand him. And he had given up a lot for Soda and me.
Thus we can see that Ponyboy loves Darry for the way that he has sacrificed so much to keep the family together, in spite of the way that he so often tells off Ponyboy and shouts at him.
Because his parents have died in a car accident, Ponyboy lives with his brothers Darry and Sodapop. Darry repeatedly accuses Ponyboy of lacking common sense, but Ponyboy is a reliable and observant narrator. Throughout the novel, Ponyboy struggles with class division, violence, innocence, and familial love. He matures over the course of the novel, eventually realizing the importance of strength in the face of class bias.
Ponyboy realizes that Darry is hard on him because Darry loves him.
Pony boy likes Darry because he found out the sacrifices Darry did for him towards the end of the book.