The so-called "word of mouth" mainly refers to the reaction of North American movie fans represented by IMDb. Nolan have five of his works in the Top250: "The Shadow of the Hero", "The Dark Knight", "Fatal Magic", "Shards of Memory" and "Pirates of Dreams" "Space" and "Inception" also made the top ten, showing how the British director born in the 1970s is favored by fans in the Internet period.
"Inception" actually continues Nolan's usual creative themes: blurry boundaries of reality, narrative methods that deliberately disrupt linear sequences, dark and gloomy video styles, and even the male protagonist who loves his wife is exactly the same as the previous work. Nolan has always only portrayed Gothic and introverted male hero images. The heroines in his films usually only take on the role of the actor's "spiritual support", and these characteristics have been continued in "Inception" without exception.
The most important thing is Nolan's labyrinthine narrative structure, but this can't be regarded as Nolan's first creation, nor can it be said that Nolan uses it best. From the perspective of narratology, it is nothing more than disrupting the linear time sequence. These things are not uncommon in the history of world cinema.
"Inception" is a successful film. When it first came out, Warner didn't have much confidence in it, Why it can success?In addition to Nolan's consistently good character accumulation, the cultural transformation caused by the rise of the Internet and video game culture may be the fundamental reason.
Of course I believe that many movie fans like Nolan and his "Inception" . I hope that more good works like this will appear in the future.