From Back to the Future III:
Doc: [consulting a map of the train line] This spur runs off the main line three miles down to Clayton Ravine. There's a long stretch of track that will still exist in 1985. This is where we'll push the DeLorean with the locomotive. Funny, this map calls Clayton Ravine "Shonash Ravine"... that must be an old Indian name for it. It's perfect, a nice long run that goes clear across the bridge over the ravine, you know, over near that Hilldale housing development.
Marty: Right, Doc, but according to this map, there is no bridge.
[cut to Marty and Doc standing at the end of the track overlooking the ravine]
Doc: Well, Doc, we can scratch that idea. I mean, we can't wait around a year and a half for this thing to get finished.
Doc: Marty, it's perfect, you're just not thinking fourth-dimensionally!
Marty: Right, right. I have a real problem with that.
Doc: Don't you see? The bridge *will* exist in 1985. It's safe and still in use. Therefore, as long as we get the DeLorean up to 88 miles per hour before we hit the edge of the ravine, we'll instantaneously arrive at a point in time where the bridge is completed. We'll have track under us and coast safely across the ravine!
Marty: What about the locomotive?
Doc: It'll be a spectacular wreck. Too bad no one will be around to see it.
Among other people who know Back to the Future, I often use the phrase "Marty, you're not thinking fourth-dimensionally" when people are focusing on a logic problem that can be solved by switching to a different paradigm or perspective. It's an attempt to evoke this scene as a reminder of how things that can seem to be a problem, aren't actually a problem within different contexts or perspectives that can easily be applied to the situation.