David was your bestfriend back then. Not until he met the new girl in your class, Trisha. He had been different since Trisha came. Rather than you he mostly spends time with her, which makes you hurt to the core. Trisha would sometimes bully you, saying that David always hated to be with you. And then sometimes she would hurt herself and blames you for it so that David would be mad at you.

Without having any hope on bringing the old David back, you choosed to avoid them especially Trisha.