A heist movie in which the characters infiltrate, a mind to steal an idea, as opposed to a bank to steal some money, doesn’t sound like an easy sell. But Warner Bros. had an ace in the hole when they came to market it in the summer of 2010: it came from the mind of The Dark Knight’s visionary director Christopher Nolan.

Inception was Nolan’s first wholly original film since his feature debut, Following. Inception came entirely from Nolan’s mind. If the smallest seed of an idea can grow to define or destroy you, this one grew to define Nolan’s work. So, here are 10 Fascinating Behind-The-Scenes Facts About Inception.

The members of the team were based on a film crew

When he was writing the central team pulling off the heist in Inception, Christopher Nolan based their roles on that of a film crew. The director explained these intentional parallels in an interview with Entertainment Weekly.

Cobb is the director, Arthur is the producer, Eames is the star, Ariadne is the production designer, Saito is a meddling studio executive, and last but not least, Fischer is the viewer. Heist movies are all about a team working together to achieve a common goal, and according to Nolan, that’s similar to how film productions operate: “In trying to write a team-based creative process, I wrote the one I know.”

Emily Blunt, Rachel McAdams, and even Taylor Swift were considered for Ariadne

While the casting team behind Inception was trying to figure out who would play each role, they considered a huge number of young actors to play Ariadne. They eventually chose Ellen Page, who was perfect for the role and played her brilliantly.

But before offering the part to Page, the producers looked at some very talented actors, including Emily Blunt, Emma Roberts, Rachel McAdams, Once Upon a Time’s Jessy Schram, Evan Rachel Wood, and Carey Mulligan. They even considered Taylor Swift for the role. Christopher Nolan would later cast a different pop star (Harry Styles) in his WWII epic Dunkirk.

Joseph Gordon-Levitt performed most of his own stunts

During the intricate fight scene in the rotating hallway, Joseph Gordon-Levitt performed all but one of his own stunts. Sometimes, it can be difficult for the studio when an actor wants to perform their own stunts. If those stunts are as daring as the ones that Tom Cruise does in Mission: Impossible movies, then it can be tricky to insure the actors.

Cruise could break his leg, like he did while shooting Fallout, or even worse. So, letting him do the stunts is a gamble. However, Inception’s spinning hallway was designed specifically for use in the movie, so safety was a factor from the beginning.

No second unit was hired

Most movies – especially big-budget studio movies – have a second unit to capture the less important shots, like the ones that will provide the basis for CGI-filled sequences. However, Christopher Nolan didn’t hire a second unit for Inception. He wanted to shoot it all.

Every single shot that appears in the movie was crafted by Nolan himself in conjunction with his go-to cinematographer Wally Pfister. Nolan had previously refused to hire a second unit for The Dark Knight. He has a very specific vision for each of his films, so he can’t just delegate certain shots – even if they’re just B-roll – to a totally different unit.

Tom Hardy was cast based on his performance in RocknRolla

Christopher Nolan decided to give Tom Hardy a role in Inception – and in his subsequent movies The Dark Knight Rises (as the iconic Batman villain Bane) and Dunkirk (as Farrier, a Spitfire pilot who assumes command when his leader is shot down), too – based on his riveting performance in Guy Ritchie’s underrated crime caper RocknRolla.

However, Hardy assumed that Nolan had cast him based on his star-making portrayal of the titular prisoner in the hard-as-nails biopic Bronson. So, when the actor arrived on the Inception set and started talking to Nolan, he was surprised to discover that the director had never even seen Bronson.

The snowbound sequence was inspired by James Bond

Despite starring a one-and-done Bond – Australian model George Lazenby – On Her Majesty’s Secret Service is often praised by filmmakers, including Steven Soderbergh, as the best James Bond movie. It might not be the most entertaining or iconographic of the movies, but it is considered to be the most technically proficient and beautifully crafted; the only one that is a real “film,” and not just a fun action movie.

Christopher Nolan is among the filmmakers who have praised On Her Majesty’s Secret Service as the best Bond outing – so much so that the snowbound action sequence in Inception’s third dream level was inspired by it.

Christopher Nolan didn’t research dreams while writing the script

Although it makes plenty of definitive statements about the nature of dreams, Inception is not the product of rigorous research. In fact, Christopher Nolan didn’t look into the science of dreams at all when he was writing the script. He explained to Collider, “I think a lot of what I find you want to do with research is just confirming things you want to do."

“If the research contradicts what you want to do, you tend to go ahead and do it anyway. So, at a certain point, I realized that if you’re trying to reach an audience, being as subjective as possible and really trying to write from something genuine is the way to go. Really, it’s mostly from my own process; my own experience.”

Most of the visual effects are practical

In true Christopher Nolan fashion, most of the visual effects in Inception were created using practical methods. For example, the crew actually built a giant hallway rig to make the hallway spin around with the actors actually fighting inside it as it moved.

No CGI was used in the creation of the zero-gravity sequences, either, as these were actually filmed in zero-gravity conditions. The Penrose stairs (the staircase that keeps going up continuously, despite going around in a single square) were also built practically. All in all, Inception has around 500 visual effects shots, as opposed to regular blockbusters, which can have more than 2,000 VFX shots.

Christopher Nolan first pitched the idea in 2002

Christopher Nolan first conceived the idea for a movie set in the dreamscape when he was making Insomnia. In 2002, when that movie was completed, Nolan went around various Hollywood studios, pitching this idea. Initially, Inception was conceived as a horror film. In the writing stage, this angle was dropped in favor of making it a heist movie.

Some studios were interested in 2002, but Nolan felt that he’d do the script justice if he wrote it on spec (in his own time, not to meet a deadline or fulfill a contractual obligation), so he decided to take a couple of months out to work on it. The final film wouldn’t reach theaters until 2010.

Leonardo DiCaprio was the only choice for the role of Cobb

Usually, when some movie producers sit down to start casting a project, they’ll keep a few actors in mind for each role. That way, if their top choice is unavailable, they have a few more options to fall back on. However, for the lead role of Dom Cobb in Inception, writer-director Christopher Nolan and his wife/producing partner Emma Thomas only had one actor in mind: Leonardo DiCaprio.

DiCaprio’s involvement in this film, and the strong working relationship he developed with Nolan, led to media speculation that the Catch Me If You Can star would play the Riddler in Nolan’s then-upcoming third Batman movie.