Argh, I wish I could find a citation right away but having trouble in search - while I get the example (memorize X amount of numbers) and discovering there's an upper bounds is understandable. But what I had in mind was a musical instrument, in that there are a finite number of notes and how those notes can be played in a harmonious fashion. The study I saw, or think I did, showed that when performing a music solo some musicians were able to turn off the 'active' part of thinking about the notes to play. It was some different mental channel. That would, to me, explain how a guy like Freddie King could play a song like Hideaway for 45 minutes with his band and people would enjoy it.

Quite a cool article. Lots to consider. Phrase around my 'woodshed' was always "Practice makes better" though because perfect and guitars don't really ever align.