@JoshFossgreen mentions several times in the early lessons (the only ones I have seen so far, LOL) that he does not want us to get stuck, but to keep moving forward. He (and others on here) also have said that doing the Fast and even the Medium speed workouts are not really mandatory.
So how do you know when the right time to move to the next lesson is? Last night’s lesson was the first one where I had actual trouble keeping up with he fast workout (Sweet Home Alabama) and I’m not sure where exactly the break point is between an acceptable level of mistakes versus a need to do the lesson 1-2 more times until you have it down. I don’t want to move ahead too fast because I have a feeling the difficulty level will spike before too long (I have read a few concerning things about Billie Jean…) so I don’t want to realize that I should have mastered some basic skill already and I moved on too soon.
FWIW: Maybe adding in a sort of “exam” at the end of each module might help out. Just a sort of bonus lesson where Josh plays a line and tells the student that if they can play it the same way without messing up, they should move on, but if not, they should repeat lessons. Just some way to gauge if I am really doing as well as I think I am.