[Philip Lyon]

It's not like all guitar teachers teach a specific technique and require strict adherence to it though. I happen to be a guitar teacher, and I try to give my students helpful tips based on my own experience and when I think it could help them, but I'm not going to be like "the thumb must never come over the neck" especially when it doesn't matter. A classical guitarist would say something like that, but yeah, Hendrix did it and used it to play extra notes in chords, and crazy fast players like John McLaughlin also let their thumbs stick out past the neck, but criticizing technique is pretty useless when he's going to be better than 99% of guitar players. I think that absolute adherence to technique is generally going to be found more in the realm of classical guitar playing, where they've been doing it for hundreds of years and may well have figured out how best to do it, but classical guitar is a totally different animal than steel string.

Anyway, I don't think the idea of doing whatever comes most naturally to you at first is the best practice. I remember having to relearn my picking technique once I started wanting to play more technical music, and I observed how other people did it and read about it and wound up adopting the style that seems to be most common and my playing improved greatly for it, despite having to overcome the road bump of retraining the technique.

[dell]

I no longer play electric, but I used to have a '72 Les Paul gold top and a https://www.google.com/search?q=fender+super+six+reverb&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=Pax3T7eYBdK10AHK9pyyDQ&ved=0CFgQsAQ&biw=1600&bih=770 amp. I sold them by 1980, and I have worn my boots backwards and have kicked myself around the block since then. The Super Six Reverb turned out to be a fairly rare amp. They were made from '72 to '79.
I play only acoustic guitar and keyboards now, and have a fairly decent little basemant studio and have done some pretty decent tracks, but am currently a little out of practice.