Instructing private and instrument students all day does nothing in terms of keeping my brain used to processing and remembering large amounts of completely new information. All it does is solidify what I learned before (going over and over the same material), especially if 5 of 11 students are all at about the same lesson and on the same day...Simply repetition. Sometimes you'd learn something new or review old material every once and a while to freshen up for a new lesson...
Spending a full day going over almost the same stuff over and over is completely different I think, than spending a full day of going a new concept or rule every minute for 8 hours a day, every day. Just my opinion that when your brain retraces old neuron pathways it is much different than constantly building new pathways...
Im two days away from finshing systems and its almost too easy these days...just that first week I could definitely remember my head being super exhausted by the end of the day...not so these days...