time passes quite fast in this movie.

With all due respect... you say words to the effect that you have a hard time following the story and wonder if it is poorly edited, or otherwise in a quite broad minded display of fairness you pose the possibility that perhaps you may lack the required attention span, and yet in the last sentence you admit that you are writing this very review simultaneously to watching the movie!

This is not by any means the only example on these IMDB pages, of a relatively new phenomenon whereby some people do not seem able to sit through a movie without hauling out some personal electronic device they carry and communicating with acquaintances, checking their email or social websites, or using reference sources like IMDB in a sort of interactive role to the movie experience and at the same time believing that despite their divided attention, they are 'watching' the movie.
I've read plenty of posts on this site in which the writer glibly informs the reader in his post that he/she is watching the movie 'right now'!

That just doesn't work. You miss things. That's why people have car accidents while using their cell phones, they missed something important that was happening, that they should not have missed.

I think you're right. But remember that the story is being told as recollections of Nobile in his almost-dreaming state. The passage of time in dreams and distant memories is very different than in real-time.

There's nothing to indicate the original poster is inattentive or stuck on their phone. They just might be not used to this story-telling style - the story told by jumping around memories, as they're discussed by imagined characters, or ghosts.