Inception Art of the Dream), and particularly the ending, is meant to leave you thinking and questioning the nature of reality.
Is Cobb still dreaming and are his team and family (and maybe Saito) all projections? Or is the job completed and is everyone back in reality and everything is happily ever after? Will the spinning top keep spinning or was it about to fall over just before Nolan cut to black? Part of the genius of the movie is that we will never know for sure (absent a sequel). However, the top does start to wobble and it is never shown doing that in the dream world. And, while the top wobbled, the kids were dressed the same (or very similarly) and in the same positions in the yard as when Cobb sees them in his dreams. What does this mean?
After two viewings I can tell you that from the moment that Cobb and Saito (seem to) wake up from limbo, Nolan very purposefully shifts the film into an ambiguous state that leaves it somewhat open to the viewer’s perception and interpretation of that perception – two big themes of the movie, coincidentally enough.
From the moment Cobb and Saito wake, there is no more dialogue between the characters and few shots or images that would concretely explain or prove one interpretation.
- When Cobb gets to a dream that he desires for his future, the top in his dream falls, signaling to Cobb that's its OK to stay.
- Maybe the "Inception" refers to Cobb (or Mol) planting the idea in his own mind, that its a logical preference to live in a dream. Even when he "knows" its only a dream. Remember it was Mol's top. Suppose she "Incepted" the idea into Cobb that the top in his dreams falls.
- Why do we simply accept the idea that in a dream the top will always continue to spin? Why couldn't we dream that the top stops spinning? Was the idea that the top keeps spinning in a dream an "Inception" planted by Cobb or Mol?
- Was Saito truly powerful enough to make one phone call and end Cobb’s problems or was that just Cobb in limbo projecting his subconscious wish to go home? You can argue logistics all you want, but if it’s said that Saito is a powerful and wealthy man (he bought a whole airline on a whim), then there’s reason enough to infer that he could bend the legal system for Cobb. Rich powerful people bend laws all the time.
- Is there something unusual about the immigration agent? If he’s staring at Cobb, is it because his job is to look people over and scrutinize them? Would you want immigration letting people through without face-to-face scrutiny? But remember in a dream, you start to draw the attention of the projections of the "dreamer." Not much of an answer here.
- Did Cobb’s father (Michael Caine) arrange to meet him at the airport or is he there because he’s Cobb’s projection? There is a phone on the plane, so Cobb could have easily arranged for pickup. This was also an intricate plan they were hatching, so arranging for airport pickup would probably be on the to-do list.
- In early dream scenes Cobb is wearing a wedding band that doesn’t appear in the “real world” scenes or the end scenes in the airport – does that mean the ending is “reality?” Of all the "clues" discussed, details like that are certainly the best evidence that there is a real world and that Cobb does live in it at times – such as when he isn’t wearing a wedding band.
- At the end, Cobb’s kids seem to be the same age and are seemingly wearing the same clothes as they were in his memory of them – is it “proof” he’s still dreaming? At the end of the film Cobb’s kids are wearing similar outfits to the ones he remembers, but their shoes are different. As for their ages: if you check IMDB, there are actually two set of actors credited with playing Cobb’s kids. The daughter, Phillipa, is credited as being both 3 and 5 years old, while the son, James, is credited as being both 20 months and 3 years old. This suggests that while it might be subtle, there is a difference between the kids in Cobb’s memories and the kids Cobb comes home to. That would suggest the homecoming is in fact “reality.” But feel free to debate that.
The only thing he knows for certain, the only thing that is real is his love for his kids. Dream or no dream, the love he has for his kids is a reality. And that was good enough for him, at that moment, he no longer cared if the top fell over or not. Cobb walks away from spinning top; hugs his kids; and, is finally happy.