Nolan's traits, resulting in trademarks:
The personality, it all starts here. He is first off, as we all know, incredibly gifted and a genius. But film is usually tricky with geniuses because geniuses, by nature of what they are, end up alienated emotionally if not rejected because they see a different world by and large then the masses, whom are happy to take part in our world instead of exploring defining changing and understanding it. As I was saying Film is tricky cuz it's an extreme medium, where you either make films that don't get put out to make big money or you have to cater your film towards huge audiences. Even if as smart as him most artists end up either rebellious or defiant or disconnected, Arnofsky comes to mind as someone who's brilliant but long lacked the ability to mesh with larger audiences, and seems to tailor everything to not be for mass audiences. Wrestler was a big step in the right direction and the Black Swan was a big time accomplishment because a larger audience was emotionally delivered the films themes through just audience interaction. Even so, he's a perfect example of a gifted artist trapped in the jail of feeling he either has to be inherently defiant or has to sell out each film out.
Nolan however is very at peace, he seems to engaging and genuine and is immensely comfortable operating in our world and being respectful in it while still willingly separating himself. He doesn't rebel but instead just doesn't have internet or a phone, he both works in the normal world and doesn't even care to explore or work through it, he is an incredibly thinker and the universal ideas he builds his films through make large groups of people relate. He also is incredibly thoughtful and progressive (good way not douche hippies way), so his films are built on views of the world that are just perfect for each film at it's core. After all that work, he also seems to just love film making and storytelling enough that it's not about personal accolades in any way. So he's crafted every film except Inception to work as a straight experience without ever understanding how much he's really pulling off, again many great artists fall into being no better then studios becuase they to make movies with an alterior motive, complexity belittles simple viewers and rewards re watching and allows the director to feel litteraly over people's head. I can't say enough for how much Nolan's top brand is built from not caring about brands at all...not once has he did a fim to promote himself. My favorite example is the brilliant structure he pullled off in TDK's first act when the movie is all about the 3 man crime fighting team going after the mob, and all we get is 3 joker scenes. 3 scenes where he is just toying with men that we know to be incredibly dangerous because he is fucking with our setup enemies. The result is that the film of Batman vs. the Joker doesn't actualy have it's inciting till 50 minutes in when the Joker makes his public threat/demand. The brilliance of this is how that structure just gave a sense of power and complete competence to the joker without him even being on screed, and the performance takes over our minds and the city after The mob has played out.
My point of all this being that Nolan was at lest co responsible in developing the character, was the one thorough of the brilliant direction of the Joker, and created the character's cultural phenomenon status with brilliant writing and well executed ideas. Of course Heath was made otu to be, before even his death, as the film's heart and soul through and through, Nolan had no issue allowing most people to never understand how his staging was an equal partner with Heath's execution, because all he wanted is for people to enjoy it. That selflessness allows him to approach film in a way that is so much more organic then even the people good enough to get a serious read.
And that word organic is what it's really about. He's insightful and observant and he builds everything of ideas, true expression, where as most the industry is opposite and revolves around recreating repackaging, borrowing from or paying homae to other movies, it's a field in love with itself but films nbuilt upon other films feel hallow. Not only do Nolan's films feel resonant because of their organic nature, but Nolan always ends up with innovation and true creation since he doesn't buld within film conventions but instead philosophy. He's a master visual storyteller whom, whether a small bear or the main idea of the film, perfectly understands how to deliver it through craft inted of being on the nose or worse soulless.
Another point about Nolan is, again showing much less ego then most of his peers on or below his level, Nolan does not direct in a direct manner but he actually is the opposite, giving his cast and key crew incredible freedom to create and feel part of the creation of that film. Not sure if it's a chicken and an egg thing but Nolan does the single most important thing to do as a director, he surrounds himself with immense talent and doesn't care much about being a stern leader or doesn't mind if great ideas don't come from him. As a director he allows people to create but stll has a vast sense of leadership and the team dynamic, almost all of his actors say at some point that he runs an incredible set. Now the most talented people in the world are lining up to jump on Nolan's films to make him look good, and yet an amazing amount of directors to this day don't work that way. His leadership and set management matches his storytelling.
Finally, he's just fucking fearless. Memento and following in their own way were huge risks, and Inception is without doubt one of the most daring uses of his rising brand I've ever seen. He shoots to prove new things instead of recreating old experiences.
He also trusts his audience making almost every beat visually or subtextually sold and rarely has the beat reply upon dialogue, making for a wonderful experience since you're constantly engaged, every cut is motivated and it makes the experience potent. He in general understands the subconscious brilliance of humanity and takes advantage of it, getting massive concepts into 150 minutes by cutting fast and with jumps and trusting us to put together how someone got from A to B. Inception made by a even just good director is unfathomable, it took every second and every cut to get all those rules and yet all the dynamics happening in it simultaneously. He has described himself as a beneficiary of the generation before (scorsese, MTV) developing fractured imagery, he's not kidding.
Finally, Nolan has cracked the system. He's discovered how to make his films chock full of intelligence and yet succeeding as a mass film, and he's the man for this because I always despised the accepted rule that real art is gritty in fim and action means less meaning. The Bible and Greek Mythology are created on a fantastical canvas, epic scope is in fact the best place for meaningful storytelling humanity has proven to respond in a deep way to heightened realities.