Scaring someone's the hardest thing to do, and that's why most of scary movies are not scary. They're sick, but not scary. There's a lot of sickness out there, of people who then sit there and watch it, which I think is absolutely dismaying.
Ridley ScottWhat you do, is you gradually become more and more experienced, and more and more realistic about dramatic tolerance, i.e. about how long the play should be.
Ridley Scott