Only bad actors want long scenes. Good, real-life actor's-as-characters want short scenes; quick victories. The honest actor-as-character moves through a scene to achieve her objectives with her first line; she only moves to the second line because the first line failed; and she only moves to the third line because the second line failed. Throughout the scene, no matter what the length, the good actor's attitude is “All right; one more line…but I’m sure that one will succeed.” When that doesn’t succeed, the character thinks: “I'll only have to try one more line,” etc. The actor-as-character naive optimism creates the necessary and valid "moment by moment" quality of an honest actor's performance.