A film for me begins with something very vague — a chance remark or a bit of conversation, a hazy but agreeable event unrelated to any particular situation. It can be a few bars of music, a shaft of light across the street. Sometimes in my work at the theater I have envisioned actors made up for yet unplayed roles.

These are split-second impressions that disappear as quickly as they come, yet leave behind a mood – like pleasant dreams. It is a mental state, not an actual story, but one abounding in fertile associations and images. Most of all, it is a brightly colored thread sticking out of the dark sack of the unconscious. If I begin to wind up this thread, and do it carefully, a complete film will emerge.

— Ingmar Bergman, 1960