Progress rarely proceeds in a straight line.
I've heard that before, and always get a mental image of mildly hysterical, to and fro dashing around. Probably because that's what it feels like to me. I generate plenty internal anxiety when I'm learning something new -- often not understanding what the end result is supposed to be, or even why it's important. However, after (ahem) many years I know enough about my own process to be confident success will arrive with an "ah-ha" moment. For me, good guidance involves pointing out errors I didn't recognize myself as well as pointing out correct choices I also may not have noticed. Perceiving disapproval from a teacher can really lock up my ability to make positive progress.
So, when I train a horse I keep a close eye on mistakes of both the erroneous variety and the correct variety. I know the horse is learning when he doesn't make the exact same mistake twice in a row. New mistakes are cause for celebration. The same mistake generally indicates some kind of resistance that is blocking learning. That's where I have to step in and offer assistance. Often the resistance is due to incomplete understanding or misunderstanding of what is being asked. Sometimes it's fear-based. Sometimes there is a physical issue involved. Sometimes it's a combination.
Same thing happens when I teach humans. We make progress when we feel safe enough to try -- when the fear of making mistakes won't cause so much anxiety that we stop looking at what is happening as a result of our actions and start, instead, to protect ourselves, getting locked in a non-productive cycle. Teaching is as much about creating the right environment as it is about imparting information at the right time, asking questions that nudge the student toward the goal, then allowing the student to work through the process.
Maybe "So, how's that workin' out for you?" isn't always a snarky one-liner. I'm thinking it's a good teaching aid, too. Sometimes we need to be reminded to take a look at the results of our mistakes. We could make progress!