I find there's also something similar that happens in revision--but in a mirror-image kind of way. Let's say you've completed a first (or later) draft. You're probably starting your revision with at least a few specific goals in mind: flesh out character X. Fix plot development in chapter 5. And so forth. In that sense, you're still working forward. You're zeroing in even more narrowly on Your Unique Story, and in certain ways, with each pass, the changes get more and more nit-picky, less drastic. And yet, when you get to that inevitable point of the revision where you're trying to make key, pivotal scenes work, sometimes you still find yourself making changes that reverberate. They don't just affect what happens next; you also have to fix what happens before. Obviously, you can't do that in an entirely forward-moving direction. You don't know what you need to fix in the before until you figure out what the scene itself needs. So, in that way, there's a looking-backward element to revision as well.
Forward movement: You plant a particular seed, which must inevitably unfold into a particular plant. Prune as needed.
Backward movement: You've got this gorgeous plant. Did you remember to cultivate the seed? If not, go back and put it in there.
Put another way: The beginning tells you where the end is going, if you know where to look and if you planned it right.
The end tells you what you need from your beginning and middle.
I find that I need to move in both directions to successfully craft a story. Not necessarily by jumping around in my draft--I tend to do separate rounds of forward revision on the whole novel, going back on subsequent passes to fill in earlier sections rather than jumping back to them right away and then forward again. Sometimes I'll linger on a section for multiple passes to get it right, if something is pivotal enough for me to need to perfect it before moving along.
Having said that, please note that any and all advice is entirely subjective. Your experience may vary. I also didn't mention the vast amount of fumbling that takes place. So...yeah.