That's awesome, Russell ...
For most people, learning anything typically hinges on a key piece of info or a viewpoint, that connects us to the "big picture". As a good teacher, you quickly found that "key" for John, and the door of understanding unlocked. I coached soccer for 9 years (16-18 yr old boys) and fine-tuning a player's skills was as much about reading his individual preferred learning style, as it was about soccer itself.
Nicely done, man ... the world's a better place with more music!
ACOUSTICS: Cordoba D10-CE / LaPatrie "Concert" / Takamine GD30CE-12 / Norman ST30
ELECTRICS: EP Les Paul Custom Pro / Gretsch Streamliner G2420T
AMPS: Traynor YCS50 / Peavey VK212 / Traynor AM150T
EFFECTS: Boss ME-80 Multi-effects / Ibanez WD7 wah