So what could have taken one scene and one page ends up consuming ten pages and ten minutes of screentime.
Guys like me often harp on the "Start a scene as early as possible, leave a scene as soon as possible" rule, but I'd also encourage writers to think hard about if a particular scene is even necessary. We don't always need to see A to B to C to D. Sometimes you can show us A, cut to D and leave B and C as points that we can fill in for ourselves.
If you've got a script that's 128 pages and you're convinced you can't cut any more, you're wrong. I just read a script this week that was 105 pages and jam-packed with story and character development. It was a fast moving plot that seemed to contain twice the twists and turns that I see in the first-timer scripts I sometimes end up reading.
It's amazing the blanks that an audience is capable of filling in. Trust them. Leave something to their imagination. See how much you can cut before they get confused. And true, you won't always know. If you watch DVD deleted scenes, you'll often see scenes that were cut for redundancy. Even the pros have trouble with this, but that doesn't mean it's not worth the effort to master.