British director Christopher Nolan shares with China Daily the behind-the-scenes stories of his recent movie, Inception, in a telephone interview.

Q: You have been interested in dreams since your teenage years. What is it that you find so fascinating about them?

A: I think I've always been inspired by the free creative thinking that dreaming allows you.

The significance of dreams to me is the freeing of the mind from logic. They allow your brain to make interesting connections between elements in your life, things you are concerned about.

And they allow you to make connections you might otherwise not make. That helps me in my work, particularly in writing.

Q: Tell us about a memorable dream of your own.

A: One type of dream that has been most important to my approach in Inception, is the lucid dream, the dream in which you become aware of the fact that you are dreaming.

And that is an experience I have had. It can be very frightening, it can be empowering. It is an extraordinary experience, because once you realize you are dreaming, you can attempt to control and change the dream.

That is the skill these characters have in the film.

Q: The city folding in on itself is one breathtaking scene in the film, how did the idea come to you?

A: It is a result of writing a scene in which somebody was on an ordinary Paris street and became aware of the fact that he could do anything with the world around him.

I was immediately drawn to thinking what would be the first impulse of an architect - Ellen Page's character is an architecture student - in such a situation.

The first thing I felt she would do is to try the extreme manipulation of the geometry of the street. Lift it up and fold it over and allow gravity to stay in place on each plane. That felt to me like a fascinating geometry as well as a powerful idea of control of an environment. And the way we tried to execute it was to make it very mechanical, like a drawbridge of some kind.

I was very struck by the bridges in Chicago where I filmed Batman Begins and The Dark Knight. And those bridges across the street, when you see them rise, it literally looks like the road itself is in the wrong place - the road seems to stand vertically.

We tried to capture that idea of a great machine changing the geometry of the street.

Q: The film's ending leaves audiences with much to think about. Does the spinning top stop or not?

A: I cannot answer the question about the spinning top. If I could answer it, I would have put it in the film.

I think the most important idea emotionally at the end of the film is that he (Dom Cobb) is ignoring it, and he isn't looking at whether the world is false or not.

Q: But personally do you see Cobb's fate as a happy ending or a tragic one?

A: I would always prefer to see a happy ending. I think emotionally that is what we create and that is what we are looking for in stories.

Q: The film reminds some of the Matrix, is there any connection between the two?

A: Matrix is a huge inspiration for Inception.

Primarily, the way in which it involves audiences is a very basic philosophical question but a very important one: How do we know the world around us is real?

I thought that would be something to aspire to as a filmmaker - to try to involve the audience in a philosophical and interesting question in an entertaining way.

There were a lot of films when the Matrix came out that explored the idea of 'How do we know what's real around us? What is the nature of reality?' The 13th Floor was one, Dark City was another, and my own film, Memento, to a certain extent played with those ideas.

But I wanted to do a film where you turn that on its head, and try to involve the audience in the process of creating an alternate reality for unsuspecting characters. That is why Inception is a heist movie, a film about con men, because I wanted to do the opposite of the Matrix, to have the characters and audience really know what the reality that is being created is, and make them complicit in that game.