Sir Peter Hall tells a bigger truth in a discussion about directing:
[via The Telegraph]
I’ve worked with practically all the great directors, alphabetically, from Bergman to Zeffirelli. It’s wonderful to be involved in the mystery of other directors’ work, because they’re all different.
But most will know within the first three or four days whether it’s going to work. The interesting thing is when it’s wrong they have to go on and they can’t tell anybody it’s wrong.