My own entry into the hobby was just a few years earlier, and followed a similarly confused wandering among the various forks then extant, the distinctions between them being rather vague to a tween. My very first exposure was to what I call "Red Dragon Basic", the 1977 or 79 version with a red dragon on the cover, during my time at an alternative school; my own gifted, talented, and probably-somewhere-on-the-spectrum self had not done well in middle school, so my well-meaning parents went shopping, and placed me there for a while. It was great for my imagination but didn't help at all with my social awkwardness and/or backwardness when I got mainstreamed again a couple of years later, and was dumped right back into the adolescent shark pool with barely any idea of how to swim... but that's another story.

(Just for bonus wtf, while the box was in full color, TSR apparently didn't have the budget in those days to do the same with the book cover, which was the above art all in shades of blue. So its full identifier in my head is "red dragon, blue cover". Go fig.)

One of my few clear memories from those first fumblings included a run through that classic old module, B1 "In Search of the Unknown". We came in through the basement, er, cave level, and as some of you may recall there was one of those random-magical-effect inflictors that early modules so loved, a mica outcropping that you were supposed to chip a flake off and put in your mouth. When the other players urged me to go through this, I was sure both IC and OOC that this was some sort of hazing/initiation ritual, but gamely went along with it. (I have no idea what I rolled.)

A few years later, after I'd left that school, I jumped from that edition to what I figured was the next step - "Expert" edition. And so it was, technically, though its precursor was not the "Basic" that I had played, but the new "Basic" that had come out by then, and which Gryph describes above. This led to some confusion, of course... which only got worse when I found a book that did seem to match up with the sort of "Basic" I was coming from, though it wasn't actually a rulebook at all. No, it was the Monster Manual for AD&D ... first edition, we'd call it now, but I had no clue.

From the seed of the MM, I managed to acquire the rest of the AD&D books - the Player's Handbook and the Dungeon Master's Guide - and read them obsessively cover to cover, for lack of any actual gaming group to play with, and gradually figured out how they related to the Basic-Expert-Companion-etc fork. And then, of course, Second Edition came along and... well, anyway.

One final note: when Gary Gygax died, I tried to host a session of 1e AD&D with my then-current group, in his honor. (My bare-bones setup had the PCs protecting a halfling village against a band of goblin raiders; the villager who'd hired them kept fussing about them numbering only six, and asking if anyone knew where he could find a seventh, which was apparently "traditional.") In truth, we barely got past character generation, and I was struck again and again by how many things I'd come to take for granted were simply missing - more by that than all the superfluous grognardy detail about pole arms, etc.