Not trying to toot my own horn here or anything, but I didn’t really have any trouble grasping anything Christopher Nolan did in “Inception”. The film is probably rightly being considered “smart sci-fi”, but it’s nowhere as “complex” or “hard to understand” as some are making it out to be. I will grant you that if you happen to get up and go to the bathroom at the most inopportune time during the film’s two and a half hour sit, you may have missed a very important plot point, in particular if you took your ill-advised trip somewhere in the film’s second half, when the gang dives into Fischer’s unconscious to mind-rape him. In that case, you’ll find this very helpful.
The boys at GiantFrigginRobots have come up with a very shiny, color-coordinated diagram to explain the five levels of dream “world” that exists in Nolan’s “Inception”.
(Look, if you’re still confused after looking at this, the only thing I can say to you is, stick to watching reality TV shows on the E! Channel. Your brain is already mush, and there is no salvation awaiting you.)
And of course — SPOILERS BELOW if you haven’t seen the film yet.