Leonardo DiCaprio, Inception

You’ve seen the commercials filled with surreal, phantasmagorical imagery. You’ve read the reviews full of effusive praise or total confusion. Heck, maybe you’ve even bought a ticket for Inception (the movie, released only last week, is on the verge of grossing $100 million) and have your own opinion about this mind-bending puzzle box about thieves who infiltrate the heads of the rich and powerful and steal precious ideas (or plant new ones) by creating elaborately manipulative dreams.

But if you think that merely pondering the movie requires some serious brain gymnastics, just consider what it was like to star in it. Leonardo DiCaprio explains that shooting the film was both a mental and physical challenge. Nolan, a stickler for naturalism, insisted that his actors and crew bring his vision to life without the use of computer-generated effects as much as possible, from making Joseph Gordon-Levitt perform zero gravity fisticuffs inside elaborate, rotating sets to asking the cast to feign peaceful slumber inside a van during a high-speed chase. “Actually,” says DiCaprio, “the van sequences were much easier than doing five pages of dialogue and the whole set is tilting and we have to hold onto a bar in order to not slide off the stage.”

For more on Inception, pick up the new issue of Entertainment Weekly, on stands July 23rd.