Altho I agree, in part, with all that's been said, I have to say that I learned guitar from somebody who knew NOTHING about it....myself. For me, music theory might as well be Swahili, my chord repetoire and fingering are both limited and I still, after practicing (and playing...and flubbing) for 40 years, can't master a Bminor. But I love to sing, I get great enjoyment out of accompanying myself on the guitar and dulcimer, and other people seem to like it too.... I have a tremendous respect for those who have mastered their instrument, whatever it is, physically, mentally and emotionally....but there is a lot of pure pleasure to be had from just making music, even in a limited, or inexpert way, IMHO (and with my limited skills it is very H indeed!).