I've had this thing less than a week. I sort of made a breakthrough today, something so elementary I should have known this over 4 decades ago but better late than never.
I did at least know about triads and building chords, a little bit anyways. I was messing around with the keyboard and my guitar in my lap. Oh, and by the way, my new strat has become an absolute delight to play now that I've filed the fret ends, polished the frets and set it up. It plays as nice as my CV50 tele, weighs 1.25 pounds less and the ergonomics are ridiculously comfortable. I digress.
I was working on matching the chords to my fretboard. C major. D minor. E minor. F major. G major. A minor. and the one that used to get me confused, the diminished chord. Suddenly it became clear. An "ah ha" moment. Bear with me. Rather than working on the 6th string root, I worked on the higher strings triads. For me, the most natural place to start was the B string, 1st fret C. Then I worked my way up the scale, then back down. Then I did the next three strings B G D. Then the A D G and finally the E A D.
If I got stuck, I played the chord on the keyboard, named the notes and found them on my guitar. The reinforcement was immediate and illuminating. This is probably old hat to those who began on piano/keys but it is a revelation of sorts to me. Anyway, nobody around me is into music or cares, so I thought I'd share somewhere it might at least amuse somebody