Short talk by Hadar Shemesh explaining that mistakes indicate habits are not yet rooted; recognizing and spotlighting mistakes helps identify the ~20% of effort that yields ~80% of fluency (focus on high-impact forms, pronunciation, and vocabulary).
Chapters
When you make mistakes, it means that the habit is not rooted. The right form, the right pronunciation, the right words. Okay, so it just means that you haven't used it enough, you haven't understood it fully. And when you recognize the mistakes without shying away from it or avoiding it completely, but you just, like, decide to put a spotlight on it, it's really learning what your 20% is. And by 20%, I mean the 20% that would get you 80% of the results, the 20% that you need to focus on and learn so you can achieve 80% of your fluency goals.