Kate Winslet initially thought 'Steve Jobs' would be "impossible".
The 40-year-old actress is thankful director Danny Boyle allowed extra rehearsal time when making the biopic - in which she stars opposite Michael Fassbender as the late Apple entrepreneur - because scriptwriter Aaron Sorkin's dialogue was so complex.
She said: "I do remember reading it and going, 'Wow this is really impossible, we're going to have to learn this like a play.' We wouldn't be able to leave anything to chance.
"I knew it would be a unique experience, very different from anything I'd done before.
"The rehearsal process itself was so crucial, to make mistakes and figure out what we didn't want to do.
"By the time we got onto set to film it, we'd done it at least 100 times."
However, director Danny credits Kate - who plays Jobs' friend and right-hand woman Joanna Hoffman - with being the "enabler" who pulled the film together thanks to her knowledge and experience.
He said: "She helped Michael the way Joanna helped Steve. She would constantly solve problems on set.
"She's a bit of a filmmaker on the quiet, she understands all the business."
However, the 'Dressmaker' actress has no desire to step behind the camera and direct.
She told The Lady magazine: "I think I would find it really stressful."