I was considering giving lessons again, and came across something I wrote years ago when I was trying to put together some online materials:
One thing I don’t miss about giving one-on-one guitar lessons is that nearly every guitar-star wannabee I attempted to teach “knew more about music” than I did. Which is to say he (almost always a “he,” so don’t get offended, ladies), had it on “good authority” (as often as not a Jack Black movie) that Rock and Roll was all about attitude, and that understanding music theory only gets in the way.
But the fact is, unless you understand the relationships among notes and chords on the guitar, all the emoting and head-banging in the world will not make you a decent guitar player, any more than having strong opinions about triangles will help you get a good grade in Geometry class.
Just sayin’ . . . .