Are we bounded by a "maximum" learning rate on a day-to-day basis?
I have come to understand through your great podcasts that for humans to "learn" we need two things: A) To be alert and focused when we are working on what we want to learn during the day, B) To get sufficient amount of quality sleep (probably "deep sleep" in particular) so that the neural signal pathway(s) that were active during that time of the day get crystallised through repetition. This has made me wonder on whether there is a hard upper bound of how much we can learn on any single day. Is it possible to stay "focused" for many activities (hours) throughout the day, and to what extend can we even manipulate how strongly and for how long can we stay focused? Is there perhaps a physiological/neurological limitation (like the ultradian cycles)? Or, is there a perhaps a limit of how much can get crystallised during sleep? I believe this can inform how we create our learning schedules in our lives. If, for example, one wants to start learning three things, e.g., playing a musical instrument and blogging and preparing for a test at the university, assuming they can dedicate at least 3 hours in each activity on any single day, is it possible to learn at the same rate as if that person was attempting to learn only one of them? Is it faster to learn 1 by 1 and sequentially, rather than all in parallel?