Joseph Gordon-Levitt's lack of preparation
Joseph Gordon-Levitt had "less than a week" to prepare for his role in '50/50'.
The 30-year-old actor - who plays cancer patient Adam Lerner in the movie - was called on to the project when original star James McAvoy was forced to pull out following a family emergency, but Joseph admits he would usually "prepare for months" for such an intense film.
He said: "I would usually prepare for months for a part like this and this time I had little less than a week. But there were certain advantages because sometimes when you have that much time you over-think and you second guess and you get nervous.
"I didn't have time for that, and I had to just go with my first instincts, and it worked."
The '500 Days of Summer' star explained he is drawn to roles that "inspire" him, and it doesn't matter whether he is appearing in a high or low-budget movie.
Joseph added: "I just like to do work that inspires me, and I don't pay attention to whether it's a high or low-budget movie.
"I do movies like 'Brick' or 'Mysterious Skin' for the same reason I do a movie like 'Inception' or 'G.I. Joe' - because there's something in it that makes me excited and will challenge me as an actor."