What would happen if multiple people could share the same dream? That’s the high-concept idea at the center of Christopher Nolan’s action thriller Inception — a story that, Nolan told AMC News, he occasionally got lost in himself. But, he says, that’s a good thing, because the film is about getting lost in the layers of the mind. Inception stars Leonardo DiCaprio as Cobb — an “extractor” who can join in the dreams of others, steal secrets from the darkest corners of a person’s subconscious, and plant ideas within dreams. DiCaprio told AMC News that Nolan and his “highly ambitious film” about the power of the mind motivated him (and, sometimes, confused him) during shooting. While working on the film, Inception co-star Joseph Gordon-Levitt said he became more intrigued by the mind’s ability to create visually and sonically lush dreams and wondered how much of that ability we could harness for use in our waking lives.