Harley had always been in your father's way of getting rid of you. He fears your existence that it will give Harley a reason to reform. Now she's gone back to Arkham thanks to the good old Batman. He decided to take the chance..

. You already knew of your father's wrath even if your mother was blind to it so when he hurt you, you knew the best course of action was to run and so you did. Your wounds though did not let you get too at but instead of never waking up like you thought you woke up all bandaged up in the bat-cave. The Batman looming over you, he knows who you are, he also knows you are not a bad kid.

"Hello there, What is your name?" Bruce already knows all this but he wants to gain your trust first so he doesn't end up scaring you off.