Okay, well I just saw "Inception" since it came out on video. And again, like before, it was completely mind blowing. Not only is the movie a great thriller, but it also has a very important message in it that not many people can catch the first time watching the movie. Watching it the second time, I was inspired to give my intake on the message. I may be wrong, but this is just my take on Nolan's message.
Obviously, the only message that can be attempted to come out of this movie is about dreams. Now the original plot of dream invasion and inception itself is not the point that I think he symbolically is trying to accomplish is the complexity and meaningfulness of dreams. First of all, dreams are not just escapes from reality but in fact they are wishes and wants from your subconscious. Like the old Disney song goes, "a dream is a wish your heart makes." While it is more complex than this, it is the perfect summary of dreams. Simply, dreams are thoughts in your subconscious that are things that cannot be achieved in reality. In your dream, you can be a completely different person, the person you have always wanted to be. You can do things not possible in reality, from something as simple as flying to something as complex as owning your own multimillionaire business. It's as simple as that. Your dreams can tell you what you really want, what you really need, and almost give you the steps to doing what you want. Have you ever thought, "I wish I could...?" and then you dream about it soon after? DREAMS. Have you ever thought that you want to achieve something but couldn't think of how to do so? Soon after, you dream of achieving it and learn the steps; weeks later you are one achievement better than before. DREAMS. All I am saying is that dreams are not just escapes from reality but they are also life-changers. Most people say that they became famous or successful or complete because of a dream. So there is my take on dreams, but that's just one mind in billions that saw the movie. I may be wrong, I may be right, but all in all, from experience, I feel that this is true about dreams and this is what Nolan wanted to show others.