My username tells you how far back I go. It was a time when AD&D (retroactively referred to as 1st Edition) was it. You played AD&D or you collected comic books. Needless to say, to paraphrase what George Lucas said about Star Wars when compared to Return of the Jedi as it was being filmed, your imagination can open plenty of doors, but when you are limited by the fact that you're in a new world, you tend to stay in one corner of the sandbox, too afraid to try out things that nobody else is trying, either. All I remember is thinking that it took Gary forever to get to the point on many topics and one couldn't tell at times (particularly in the DMG) when Gary was trying to even make a point or if he was just wandering. But again...new territory for all then, even Gary. And yeah...looking back it was correct for DZ Cook to put an emergency brake on Gary's methods of organization, where the rules covering a single aspect of the game were scattered over two or more books and different parts of those books.
For me, my first period of not fitting in occurred upon the release of 2nd Edition AD&D. I cannot speak for everyone, but I do remember every original AD&D player I knew, including myself, wondering "WTF Gary" - not then knowing of course that Gary had skipped TSR back in 1985, because newspapers and the news zines didn't carry these kinds of stories (and still don't) and the excruciatingly slow flow of information regarding the RPG world if you couldn't afford a subscription to Dragon Mag (which I couldn't). Not even cell phones then unless you were a suit, and forget anything even remotely like internet. All I remember is that our group and outside contacts (read: conventions) panned 2nd Ed instantly without having even perused it, of course, because it meant that support for 1st Edition was going away, and we suddenly felt like we all needed to mow about 20 lawns if we wanted to be able to afford even one basic 2e book. We felt "basely betrayed".
A bit of a confession, though. I had already found Strategic Publications Inc (SPI) and their flagship RPG, DragonQuest - which I still play to this day - back in 1981, and had relegated AD&D to the backshelf. Not because I'm a stickler for "old stuff" but because older players which I was in contact with then, who had gone on to college, had discovered DQ and turned me onto it, particularly the absolute logic behind most of the major game's combat, magic, and XP systems; a welcome break from the arbitrariness that was AD&D. I suppose that all 2nd Edition AD&D really did - because I never did buy any of the rulebooks - was affirm my separation from TSR altogether (until the fiends acquired SPI in 1989 and, with the exception of a watered-down 3rd edition publication - snuffed out DQ as a hobby store-bound product forever). The only reason I even own 3.0, 3.5, 4e, and 5e PHBs is because people that I knew were or are playing those systems.
I am now - at this very moment - experiencing what I feel easily qualifies as a second period of not fitting in. I don't really dig all these 3-letter covert operational code names, like OSR, OGL, SRD, etc that are tossed around as if their users learned them in a middle-school English class last week and I'm suddenly a square because I have no idea what in hell they're talking about. I never did podcasts, for many different reasons. My gaming world is totally and unashamedly unaffected when I hear announcements like "BigDog KoolGamer has come out with the seventh supplement for Kagreshikia: Eve of the Chainsaw Dimension Hopper Outlaw T-Rex Poachers". I don't know and certainly don't care who BigDog KoolGamer is, or what he/she's pushing out, quite simply because I'm suddenly made to feel quaint, like that there was some kind of mandatory military briefing regarding TTRPGs that I was somehow expected to attend and didn't get the (e)memo or text for. Forget supplements; I feel like there's a brand new system coming out about every 83 minutes. Even if I was that loaded financially, and even if I had a library the size of the grocery store of your choice to keep all this stuff corralled in, nobody in possession of even a fraction of their marbles could seriously expect me to keep up with it, or even one eighth of it. My definition of a hobby still entails the word "unwind" as opposed to the term "pucker up".
You know what my entire TTRPG world is? My dice bag, my Chessex hex/square reversable mat, my three sheets of plexiglass, my two sets of Vis-a-vis wet erase markers, my 280+ hand-painted miniatures and my 800+ unpainted but Krylon-primed miniatures, and my (mostly) worn rulebooks and supplements for about eight gaming systems, ALL of them - I might add - in hardcopy and purchased in a gaming store or online. At times, it might also include ESV: Skyrim, Diablo II, and the old Commodore 64 game The Sword of Fargoal.