I enjoy the idea that Batman knows the identity of joker and consider it as not important. However, I consider that should be the only thing we know about Joker’s identity. Please stop giving him an original story. Also, even though I consider joker’s identity as not important at all, I consider everything that joker had done is done by one individual. The continuity matter. He does not have any characteristics such as this one just want a laugh and that one wants to kill. He wants everything at the same time. He wants to mean more to Batman, wants to mean nothing and everything to Batman at the same time. All these opposite thoughts should come form the same individual. Such confusion/unpredictable/irrational is the reason Joker is such a great character.