ELLEN PAGE as Ariadne and LEONARDO DiCAPRIO as Cobb in Warner Bros. Pictures’ and Legendary Pictures’ sci-fi action film “INCEPTION,” a Warner Bros. Pictures release. Photo by Melissa Moseley

Known for his meticulous attention to detail when doing research for a movie role, actor Leonardo DiCaprio admits he was at a loss when it came to preparing for the part of Dom Cobb in director Chris Nolan’s latest film, Inception.

“This is a film about dreams, but I’m not a big dreamer. I never have been,” DiCaprio said at a press conference in Los Angeles. “So I decided to take a traditional sort of approach to preparing for this film. I read books on dream analysis, I read Freud’s Interpretation of Dreams. None of it was working. Then I realized this was Chris’ dream world. It has its own structure and its own set of rules. So I went to the source and started asking him questions. Being able sit down with Chris for two months before we started filming to talk about the structure of his dream world and the rules that apply in it was the best preparation to discover who Dom Cobb was.”

Inception tells the story of an elite team of dream thieves, lead by Cobb, with the power to steal even your most deeply hidden secrets by entering into your subconscious mind when you are fast asleep. A wealthy businessman hires them to take their skills one step further and actually sow the seeds of an idea into the subconscious of a competitor that he wants to ruin. While such a procedure may be possible, it will require Cobb and his dream team to go deeper into the human mind than they’ve ever been before, and there is a good chance they won’t all get out alive.

Knowing the mind and motivation of his character may have helped DiCaprio find the soul of Dom Cobb, but nothing prepared the actor for the mental and physical demands of actually filming Inception. “You read the script and you discover this highly entertaining, complex thriller where anything can happen, but you still can’t figure out how it’s all going to work on film,” he said. “Then you start seeing the sets and the locations and get a visual reference for what’s on the page and it all starts to fall into place. That’s the magic of movie making. One day you’re in filming in Paris and a few weeks later you’re in the mountains of Canada doing something completely different. It gave us a visual reference for everything that’s been imagined on the page.”

DiCaprio credits Nolan for going the extra mile and creating a physical world for his cast to inhabit rather than simply film them in front of a green screen and fill in the mind-bending details of the sets in post-production. A critical scene between Cobb and Robert Fischer (Cillian Murphy), the man whose brain they are trying to corrupt, wouldn’t have been as good, he said, if it wasn’t shot on an actual set. “In the scene, Cillian and I had to carry on an intense conversation while the entire set was tilting,” he said. “We had to hold on so we didn’t slide off, but we couldn’t react to it in the way you normally would; we just had to focus. It really does something to your perspective.”