While I haven't read many of the actual comics (I made an attempt to get into them during Rebirth, but didn't get very far), I believe at least one of the animated movies made references to a young Batman when he was still acclimating himself to the role/lifestyle.
It's basically meant to explore the time where his emotions were still raw, his childhood trauma still caused him internal conflict, and he's generally unstable. The time where he still has to figure out how to handle his dual personalities, lifestyle and what kind of moral code he should live by.
I expect this movie, similar to 'Joker', to be a lot more character-driven and tonally serious, which is why Pattinson was a good fit.