O.K, i get that he had to go into hiding after the Harvey Dent incident..but why 8 years?
And why is Bruce walking around with a cane 8 years later, as if his ordeal with Joker and Two-face happened last week.......? He's been injured for 8 years? What kinda injury lasts that long?
1.
Batman was not needed as much (or anymore) after the Dent Act cleaned up organized crime. Even before Bruce Wayne became Batman, Gotham's problem was organized crime, and its plague over Gotham is what drove Bruce to become Batman in the first place. With organized crime erased, Batman is no longer needed. We assume that Gotham's finest ably handled the ordinary street crime; besides, it would be overkill and/or boring to have Batman chase purse-snatchers or investigate mail fraud.
2.
Batman needs a cane because his body is paying the career-long toll of being Batman. His TDKR injuries are not really "injuries" in that he did not get hurt from a particular incident. Rather, they're ailments and conditions that are the cumulative result of repeated and sustained physical exposure, exertion, contact, etc. endured as Batman. As was mentioned in the movie, his knees have no cartilage anymore -- it's bone on bone. Basically, his body is not a car that just crashed -- it's a beat-up car with 200,000 miles on it and not much left.
8 years seems way too long of a hiatus...
Here are my reasons why the 8-year passage of time was important and/or necessary:
1. It shows how much Batman means to Bruce Wayne, and how lost Bruce is without Batman. As was said in Batman Begins, his Batman persona was his real identity, and his "mask" was his Bruce Wayne persona, the eccentric billionaire. As the peaceful years go by, Bruce Wayne finds less and less purpose in life, since Batman is no longer needed anymore.
For 8 long years, he had been living as a shell of his real self. It's almost like Bruce thinks to himself, "be careful what you wish for." The 8 years really gave him time to "lose himself," he's clearly a lost soul in the beginning of the film. It makes Bruce's existential re-awakening -- i.e., his re-emergence as Batman, Bruce "finding himself" again via Batman -- all the more profound.
If Bruce/Batman was "lost" only 2-3 years, would it really be as satisfying to see him clean up and come back as Batman?
2.
The 8 years ravage Bruce's/Batman's body. It's not just his soul that suffers -- his body really deteriorates over the 8 years. He's clearly way off his physical prime.
As the audience, we realize that the
stakes are different now. Batman's physical death is a distinct possibility now. Even Alfred sees it; he not only sees it, but he is worried that Bruce/Batman would embrace such a death, since it seems like Bruce would rather die as Batman than continue living the meaningless experience as Bruce. This worries Alfed, it worries us.
It makes him an even heavier underdog against Bane. The Batman in Batman Begins probably would not allow his vertebrae to be broken like that by someone like Bane; he was agile and skilled enough to fend off Ra's and the League. But we see now that TDKR Batman is not the same one we're used to; we see a washed-up old man in a suit getting destroyed by a beast, and we accept it. We believe it when Bane breaks old man Batman.
And again, the long exile makes Bruce's/Batman's return to glory and defeat of Bane all the more satisfying.
3.
It demonstrates how evil Bane is. Like Gordon said, Batman left and things were good for a while, but then this "evil rises." The Dent Act kicked ass for 8 years, no mob family made a single peep in the city, organized crime was non-existent. Bane basically pissed all over the Dent Act and destroyed Gotham's long period of peace. If he did that after only 2-3 years, it doesn't really show how evil Bane is, it just shows how weak the state-of-peace and the Dent Act really were.
4. It allows Gotham City enough time to "get used to" the clean streets -- which makes Gotham's fall that much harder. Even something as significant as the elimination of organized crime would require months-years for a city to fully see its effects. The long time-period of peace makes Gotham's eventual fall all the more tragic and devastating. Imagine if Gotham had been clean for 20 years -- how jarring would it be for the city to suddenly fall under a war lord?
The storm analogy was perfect in TDKR. For 8 years, Gotham had fallen into a quiet, peaceful calm. The 8-year calm set the table for Bane's storm. It wouldn't be much of an uprising if Gotham achieved peace for like 9 months, only for Bane to mess things up.
5.
It allows time for legend to grow. In the 8th year, Dent was being revered as more than a savior or even a hero -- he had reached legend status. The 8-year span shows how effective his legend was (in cleaning up the streets). On the flip side, Batman had devolved to
myth; most had all but forgotten about him. But the few who
did believe in Batman's
legend -- like Blake, the kid, Gordon -- continued to firmly believe in him; even after 8 years, Batman is not dead and certainly not forgotten.
The long 8 years makes the exposure of the Dent cover-up even more shocking, and it makes the return of Batman all the more profound and significant.
6. It allows enough time for the proposal, voting, passage, and ratification of the Dent Act. Assuming it was a unique and/or complicated bill, something like the Dent Act would literally take 3-4 years just for it to be law. And that's just to put it in the books -- it doesn't account for the time it takes to execute the law.
7. Now that the Dent Act is ratified, the 8 years
allows the city time to locate, investigate, arrest, prosecute, defeat appeal, and sentence the criminals. It's not like they were all lining up to go to jail. Finding everyone, convicting everyone, sentencing everyone would take years.
8.
It shows how important Batman's and Gordon's efforts and sacrifices were. Batman and Gordon fought
hard in The Dark Knight for a reason: they believed that Gotham could achieve a state of sustained peace, like in the period leading up to TDKR. Their efforts in TDK and their continuing efforts to cover-up Dent are not in vain, since the Dent Act has/had been cleaning Gotham up for 8+ years.
If the Dent Act worked for only 2-3 years, then it makes the final act of the Dark Knight less significant, since everyone fought and lost so much for a feeble state of peace that would only last a couple of years. The longer the gap, the more effective the Dent Act is, the more crucial their sacrifices were.
Yeah, these reasons are kind of all over the place. Some are logistical reasons within the Batman world. Some are literary reasons. Whatever.... they're reasons why I think the 8-year gap was necessary in order for The Dark Knight Rises to work.