Watching Batman Begins, something really stood out to me that Ra's said in regards to the clean slate.
Bruce finally broke that cycle of being a slave to his father, a slave to Rachel (using her as an excuse to live a normal life and not moving on after her death), a slave to Batman. And in fact the world is too small for someone like Bruce Wayne to disappear, which is why he had to "die" in order to do so.
It's interesting because I know a lot of people thought it was far fetched that no one would recognize Bruce Wayne. And Ra's basically says so himself in the beginning. But I feel that's one of the points behind the clean slate is that Bruce found a way, not just in the literal clean slate sense but also that he met Ra's challenge and moved on. Whereas Ra's could not by devoting his entire life to his cause, he became that which he was fighting against. And I think Bruce faced this same dilemma that if he didn't give it up, disappear and start fresh, he would eventually become that monster permanently as well. Ra's was slave to his cause, Talia was slave to her father's cause and Bane was slave to Talia's cause. Even Joker who called himself an agent of chaos was a slave to it. Harvey dent was a slave to chance refusing to take responsibility for his own actions."The world is too small for someone like Bruce Wayne to disappear"
Bruce finally broke that cycle of being a slave to his father, a slave to Rachel (using her as an excuse to live a normal life and not moving on after her death), a slave to Batman. And in fact the world is too small for someone like Bruce Wayne to disappear, which is why he had to "die" in order to do so.