I've been playing roleplaying games for 39 years now. A friend showed me his copy of the Dungeons & Dragons Basic Set in the summer 1977 and I was hooked right away. I believe I got my first set for my birthday that Fall. Given that it saw the publication of D&D and the global release of Star Wars, 1977 was one of the great landmark years in geek culture, up there with 1939 and 1984.
In those days, the game didn't come with a sample adventure. Instead it contained the rules, dice (I still have a very worn-down green 8-sided die which came with that set), a set of "geomorphic dungeon maps" (you can see what they looked like here), and printed sheets listing monsters and treasure.
Our earliest adventures were entirely unstructured, not unlike a video game: the character (or characters once we could manage to get together to play in a group) enter a dungeon, fight monsters, and get treasure.
But within a matter of months we started to fill in the background. We drew maps of 8 1/2" by 11" continents and worlds, all heavily influenced by the endpaper maps in Tolkein's The Hobbit and The Lord of the Rings. I continually raided my parents' office-supply drawers in search of graph paper, and burned up a lot of nickels photocopying character sheets and pages of hex paper.
The characters we played were not the optimized, carefully-designed PCs one sees nowadays in games like Pathfinder. You rolled the dice to generate the six attributes, and tried to come up with some character class those scores might fit. Assigning numbers or doing some kind of "point buy" would have seemed like cheating. To be frank, I rather looked down on some of my friends who spent hours rolling up endless series of characters in order to get one with superior scores in every attribute.
Dungeon Mastering was frankly antagonistic: the DM was playing against the players. None of this huggy Millennial tomfoolery about "collaborative storytelling." The Dungeon Master was out to kill the characters, and resorted to all sorts of tricks to do it. There were whole books full of absurdly lethal traps (like these). This kind of "killer DM" behavior had precedent from the august Gary himself: the legendary unfair deathtrap dungeon "Tomb of Horrors."
It's important to note that there was still a social contract in force. The DM couldn't just say "you're dead." He (and in those days ALL of us were "he" — I didn't see a girl at a gaming table for another six years) could make up deadly traps, invent new monsters, and cursed magical items to throw at the players, but the rules had to be followed. That new monster (I was particularly proud of the Steel Dragon I invented) could have absurdly high stats, but if a player rolled well, the monster was killable.
Another saving factor was sheer incompetence. None of us knew all the rules, but the players could master the specifics of their own characters while the bloodthirst-but-naive Dungeon Master didn't always understand what his own creations were capable of. Monsters which should have wiped out entire parties without breaking into a sweat went down easily because they forgot to use their most powerful abilities.
My friends and I played D&D off and on through junior high. I got a copy of Traveller in 1978 or '79, and that quickly took hold of my science fiction fan's soul. And then in 1981 Call of Cthulhu came out and became my primary game for the rest of high school. Both of them were more structured than our old "kick in the door" D&D games. I started to pay attention to things like plot and character motivations.
But nostalgia has a powerful pull. For about six months now I've been running a weekly Pathfinder session at my local game store, trying to re-create some of the freewheeling feel of those old marathon D&D games of the late 1970. It's quite liberating for me: I don't have to put a lot of mental effort into creating a "story" for my players. I just make up a list of random encounters and let them meet people and monsters and choose what to do. So far that has resulted in a revolution, a city sacked by pirates, and several buildings burned to the ground (because nothing says "player characters were here" like smoldering rubble).
The game goes on . . .