>> I've tried several music theory courses and quit all of them partway through

I feel like I'm a musician at heart. If I could delve into music with a purely exploratory and child-like fascination, I think I would enjoy it immensely.

But I can't fathom beginning. Every. single. intro. into. music., is a lecture forcing theory unto you as though "theory" is the very definition of "music". The consensus from experienced musical folks is to shove theory down your throat; you should not be allowed to even touch an instrument until you've drunk the "super serious music cool-aid"! Music is supposed to be one of the most intimate ways we express ourselves, and yet Western culture dictates that there is a singular method to begin exploring it, and it's far too serious and far removed from any kind of natural process.

Had my introduction to programming, starting at the age of 7, been the shoving of books down my throat about Object Oriented programming and how to write 20 different sorting algorithms, I never would have become a software developer. It took me 5 years of accomplishing nothing - and enjoying that exploratory process - just to figure out the basics. Another 5 years to begin digging into the core things that make a developer a developer. And then another 5 years (and counting, a decade later) actually learning how to tie it all together and use the acquired knowledge as a set of skills.

Music in the Western world is taught in such a way that they're trying to cram 10 years of knowledge - that you should be picking up along the way - as pre-requisite knowledge. It is taught as a job aiming to produce immediate ROI rather than skill/talent that accumulates over time.

Sample phrases from the OP that are spreading the all-too-serious cool-aid - the same things you hear from every music professional (italic emphasis mine).

>> A lot of music theory is about limiting which notes to use in your song to a small set that sound good together.

>> not all of them sound good together... Lets listen to some garbage

>> Because not all of the 12 notes sound good together, we must select a set of notes to use in a song.

>> start exploring which chords are safe to use in each Key

Why is it deemed necessary to instruct first-timers about "limiting" the notes we might use (some notes are not "safe" you know!), and telling me what does or does not "sound good". Music should have absolutely no "must"s attached to it. Let alone labelling certain combinations of notes as "garbage" - the use of that term is horrifically off-putting to someone who is looking to explore. This method of teaching completely destroys the discovery process. You tell me that "XYZ" chord is garbage, so I avoid it from day one. What if, left to my own devices, I were to discover that chord - and wind up loving it?

tldr; Teach me to play an instrument without teaching me anything about theory. Don't even teach me how to read sheet music. Just teach me how to play a few songs I enjoy. Once I can actually play with some confidence, then - and only then - bring in the information that ties together with what I have first learned hands-on. Basically, how any 3rd-world child with instruments carved out of wood would learn. No books. No sheet music. Just an instrument and a patient MENTOR, rather than a classroom teacher who's trying to make a classical prodigy out of me in record time.