If I had to guess, I'd say that you have long been a very good player that was heavily TGM-influenced. Is that close to correct?
I wouldn't say I was heavily TGM influenced, because I played a lot of competitive golf long before I'd ever heard of TGM. But I do think that prior to this very thread, I believed in order to square the club face properly (without flipping) that I need to maintain a flat left wrist and drag the handle enough to create (with my hands) forward lean.
For me this thread contains TONS OF NEW information, and has revolutionized the way I think about releasing the club. Most importantly, I now see that I can square the clubface without holding onto anything or manipulating the club head. I can square the club face by releasing from the top and staying wide. That may be old news to you, but it's totally new and eye-opening to me.
This thread also makes much more sense, for me, out of some D plane knowledge, since I can "swing left" without having to hold onto an angle and drag the handle left. I can swing left because after impact my left wrist bends and my right wrist straightens and the club head goes left much harder than it used to. Swinging left was a difficult thought for me before, because I was never a hooker, but I can now see how it works.
For most of my life I was a slicer, and despite shooting some very low numbers in competition, I never really changed that until NSA helped me fix the club face. But for the first time in my life, after reading this thread, I have hit some drives where I made contact with the ball with a club face open to the tatarget line and yet still hit a draw (e.g club face open 2 degrees to target but path 3 degrees inside out). Trying to HOLD ON, I could never even imagine how to do this, but releasing from the top makes it possible. I have hit the ball SO MUCH straighter by just trying to "go normal."