But since "Inception" hit theaters this summer there's been a lot of evidence to the contrary pointing to what seemed like a definitive answer, thanks to costume designers and their opinions and actors like Michael Caine who believed he knew the true ending.
Thankfully, we're hearing it from the horse's mouth; Nolan, who spoke to EW this week, basically said, "look you can keep going all you want, but I'm not going to give you an answer, and I'm kind of shocked you'd even ask (dummies)."
What happened to that spinning top? Did it fall or did it keep on spinning? “I’ve been asked the question more times than I’ve ever been asked any other question about any other film I’ve made,” Nolan told EW. “That’s definitely the question. It keeps coming back to that. What’s funny to me is that people really do expect me to answer it.”
While Nolan says the ending does contain clues, don't expect him to spell them out and for them to be obvious. "I get a lot of questions like, ‘Okay, did this thing earlier in the film mean that it’s all true, or does this other thing at another point in the film mean that it’s all a dream?’” Nolan says there’s no definitive answer to that question. “There can’t be anything in the film that tells you one way or another because then the ambiguity at the end of the film would just be a mistake,” he said. ”It would be represent a failure of the film to communicate something. But it’s not a mistake. I put that cut there at the end, imposing an ambiguity from outside the film. That always felt the right ending to me — it always felt like the appropriate ‘kick’ to me….The real point of the scene — and this is what I tell people — is that Cobb isn’t looking at the top. He’s looking at his kids. He’s left it behind. That’s the emotional significance of the thing.”
Asked about "The Dark Knight Rises" he calls it (as he's said all along), “the last chapter of our Batman saga.”
"I feel very glad that I’m doing another Batman film," he said. "I think it would have been daunting to sit down and write an original script after Inception. I love working within the realm and rules of our Batman world. It’s kind of nice to have someplace to go that I’m super-excited about.” He added that Inception’s success allows him to tackle another Batman without any sense of needing to prove himself: “I must say that I’m glad — I’m very, very glad — to be embarking on the last chapter of our Batman saga without any sense of obligation or duty to the studio. They did very well with Inception. So I’m able to go into finishing our story in a very enthusiastic way.”