When you shoot a scene, you remember every moment. You remember when your head went down, your head went up. You don't see little quirks, little eye movements, little lip movements. Once again, you become completely vain when you're watching it in a way that you weren't when you were shooting it. And the vanity, what it makes you focus on are everything that has nothing to do with the scene and everything to do with your own ego.
Deep attention, the cognitive style traditionally associated with the humanities, is characterized by concentrating on a single object for long periods (say, a novel by Dickens), ignoring outside stimuli while so engaged, preferring a single information stream, and having a high tolerance for long focus times. Hyper attention is characterized by switching focus rapidly among different tasks, preferring multiple information streams, seeking a high level of stimulation, and having a low tolerance for boredom.