Clint Eastwood directs movies based on how he likes to work as an actor.
The 'Hereafter' director - who starred in his first movie over 60 years ago - limits rehearsal time and rarely shoots more than one take of each scene because that is how he prefers to work when he is onscreen.
He said: "Everything I do as a director is based on what I prefer as an actor."
Although he is 80 years old, Clint - who has directed over 30 movies and is currently planning an untitled biopic of Federal Bureau of Investigation (FBI) founder J Edgar Hoover - has no plans to slow down and said he doesn't understand why any directors would ever want to stop working.
He explained: "I was always curious why somebody like Billy Wilder would stop making movies in his sixties when someone like John Huston was directing when he was in a wheelchair.
"It just depends on your abilities at that particular time of life. People peak at different times of life. There is a Portuguese director who is 104 and still making movies."