Like Toby Young's book, the movie chronicles one man's disastrous stint working at a prestigious magazine.
"People make the mistake of thinking books and films are the same thing and they are easy to translate (one into the other.) But a book is like an aid to your imagination while a film is a surrogate for your imagination. So, they are completely different things," Pegg told UPI in New York recently.
"This film, particularly, Pete Straughan, who did the screenplay, had to extrapolate a movie from Toby's experiences because the book is like a series of anecdotes," he said. "Structurally, it's not like a movie, so he had to create a film, which is why we play fictionalized characters. I'm playing Sidney not Toby."
"And I'm playing Alison who didn't exist in the book," added Kirsten Dunst, who was sitting beside Pegg during the interview. "(Who kind of is based on) Toby's secret crush or imaginary dream girl."
"Imaginary dream girl, correct. And (Straughan has) turned it into a romantic comedy. He's given it a specific genre," explained Pegg, who is best known for his roles in "Hot Fuzz" and "Shaun of the Dead."
Notable deaths of 2014 [PHOTOS]