Wallflower
Patrick toasts to Charlie for now being one of them, a wallflower. However, the irony is that while he's dubbed a wallflower, he's actually become more connected to people and to life through his friendship with him and Sam.
Brad
Brad is beaten by his father after his dad finds him having sex with Patrick. Though Brad did sleep with Patrick, he distances himself from him after their relationship comes out, even calling Patrick a "faggot." This is the irony of societal pressure and living in a world that only accepts life as it is for them.
Craig
Sam has stayed with Craig, her boyfriend, instead of being with Charlie. Ironically, she finds out that Craig has been cheating on her and she dumps him on prom night.
Friendship
Charlie has been asked by Charlie to stay away from the group for awhile after kissing Sam. Ironically, even though he's been asked to keep his distance, he defends Patrick at school from guys trying to beat him for being gay. Charlie beats them all down and threatens to blind them if they come near his friends again.
Depression
Charlie has felt a continuous depression in his life that he is uncertain of, even believing himself a terrible person for wishing death on his Aunt. Ironically, he has suppressed the horrific memories of his Aunt sexually abusing him in order to protect himself and, like many victims, blames himself until he is able to get real help to see that it was not his fault.
