Originally Posted by The Joker
Actually it was Rachel's death and the failure of his energy project that made him give up on life and become a recluse. He felt he had nothing left to do as Bruce Wayne ("There's nothing out there for me"). As Alfred reminded him, he used to talk about finishing being Batman and having a life beyond the cave, to which Bruce responded Rachel was his life beyond the cave.
Giving up Batman had nothing to do with it.
Well, Batman had something to do with it. He no longer had a good enough reason to be Batman and thus no longer had an outlet for his rage (however self-destructive it would become).
But, yeah, you're right.