Don’t worry, it’s not. And you don’t have to know Batman inside and out to objectively know the movie is, uh, let’s say, ‘inferior to the other 2 movies.’
I’m probably not the biggest Batman geek you’ll be able to find but I’ve read most of the major story lines through the years. The Dark Knight Rises was promising because it was influenced by at least 3 classic stories: Knightfall, No Man’s Land, and Dark Knight Returns. But Nolan doesn’t really delve deep into the stories to tell any of them to their full potential.
Dark Knight Return: Batman returns after 10 years. In the movie, he returns after 8 years. That’s about all they do with it. Oh, and his leg is shot. Even Batman vs. Superman made better use of this material.
No Man’s Land: Gotham is cut off from the rest of the world and overrun by criminals. In the book, it’s because of an earthquake. In the movie, it’s because of Bane and some bomb.
Knightfall: This is the big one. In Knightfall, Bane breaks Batman’s back. This was supposed to be the biggest influence but you basically just heard all of the similarities. In the original story, Bane slowly breaks Batman down with a slew of super villains before literally breaking him. Azrael takes over for Batman while he’s out of action.
So you have these 3 classic Batman stories hinted at, none of which are really used properly. They just jammed too many iconic moments into one story and none of it works.