I liked this a lot. And, if I may say, it reminded me of one of the concepts of the movie: what is real and what is not. In the movie, I go back and forth between what is real and what is a dream (and whether it was all just a dream and none of it real) and I did the same here with your fic. I don't know what your intention was in writing, but I believe there are some parts of this that are 'reality' and other parts that are sadly just Cobb's dementia.
Well done.