"Dick not only saw his parents die, but he was raised by Batman with a strict code of ethics. Whereas Batman festered with his anger, Dick did not. But Dick saw how someone like Batman was able to help him and many others. Since he fought alongside Batman, he saw how much good he could do, and therefore he has the need to continue to do it. But unlike Batman it doesn't come from some long ago need for revenge, it comes from a true desire to make a difference. Therefore Nightwing has a positive attitude rather than a negative one. But it has had impact on his persona life, and now that he's in his mid-twenties, his early decisions are demanding some new thinking."