ET's Samantha Harris sits down with Leonardo DiCaprio for the 411 on his mind-blowing new thriller 'Inception,' in regular theaters and IMAX July 16, and the superstar reveals whether or not he dreams of having kids one day!

'Inception' teams Leo with 'The Dark Knight' director Christopher Nolan and tells the tale of Dom Cobb (DiCaprio), a skilled thief who has the ability to steal valuable secrets from deep within the subconscious mind during dream states.

"Chris Nolan is a visionary filmmaker, and when he presents an idea to you that he's been mulling around for eight years and it has to do with a dream world, and it presents itself as something with infinite possibilities, you immediately get excited," Leo tells Samantha. "You say to yourself, 'Wow, I've got to be a part of a film like this.' It's pretty groundbreaking and not something you see traditionally come out of the Hollywood studio system."

Director and screenwriter Nolan tells Samantha that Leo was the perfect fit for his surreal script: "He is first and foremost a very serious, very thoughtful actor. And it's almost to him, I think, a bit of an accident, or a bit of an add-on, that he happens to be one of the most charismatic and handsome leading men."

Nolan reveals that when his cameras stopped rolling, Leo was "very relaxed… he's very funny and calm, and really a great team player."

Leo, meanwhile, tells Samantha that although his own sleep is mostly dreamless, his earliest memories are of wanting to be an actor: "That's the first thing I remember as a young kid. Ironically I lived in L.A. but I never felt like I could be a part of that club… I feel extremely lucky every day and I feel like I am living that dream… I don't take it for granted, that's for sure."

But does he dream of having kids one day? Watch the video to find out, and for more with Leo's 'Inception' co-stars Marion Cotillard, Ellen Page, Joseph Gordon-Levitt, Cillian Murphy and Tom Hardy.