I've noticed, from my own experience, if the external, emotional construction of images in a film are based on the filmmaker's own memory, on the kinship of one's personal experience with the fabric of the film, then the film will have the power to affect those who see it. If the director follows only the superficial, literal base of the film, for example the screenplay, even if in the most convincing, realistic, and conscientious manner, the viewer will be left unaffected.

Therefore, if you're objectively incapable of influencing a viewer with his own experience, as in literature..., and you're unable to achieve that in principal, then in cinema, you should sincerely tell about your own experience. That's why even now, when all half-literate people have learned to make movies, cinema remains an art form, which only a small number of directors have actually mastered, and they can be counted with the fingers of one hand. To remold a literary work into the frames of a film means to tell your version of the literary source, filtering it through yourself.

Andrei Tarkovsky

from an interview with Naum Abramov, 1970