I really like the title of this thread (GAS is done…). I wonder how many of us went through a pandemic phase of picking up more gear in a shorter period of time than we normally would during the first year of the pandemic? I know I did that. I have at times regretted it, but now feel like its okay, since I am back to one or two purchases per year and I like what I have, even though, like the OP, I also feel a bit overwhelmed when thinking about how much I don’t know or have forgotten about certain hardware.
One thing that I do, and it seems like a lot of us do, is to pull one machine out of the studio (or case closet), bring it down to the living room (or in my case up to my cabin) and sink into it. It’s really fun and rewarding. I feel a little bit like I have an “encyclopedia” of musical instruments to choose from, and each one is its own volume. I was at a used book store a few years ago and they had a pristine (basically new) copy of the Encyclopedia Brittanica’s “Great Books” set, which I snapped up and continue to enjoy here and there, sort of randomly. I like having it right there, whenever I want, even if I never come close to reading the whole thing.
I do understand that the OP wants to “make music” and that is the goal for him, which is cool. I am just saying that those who suggest he sell a bunch or most of it, might be suggesting something unnecessary and regrettable.