So I grew up in Mexico and in a smallish (non state capital) town so I did not see a gaming product on a bookshelf in my city until 2000 when some white wolf stuff showed up. Meanwhile I homebrewed a dozen systems and ran tons of games…
Start: I owned some Steve Jackson fighting fantasy books so me and my friends adapted that system to adventures set around my room… “the book case is a mountain, each one of those action figures or cutouts has an index card under it with it’s stats, travel through the mountain and defeat them”. My parents saw us moving figures around, rolling dice and subtracting health…
Late 80’s to early 90’s: My parents told my Aunt and Uncle about what I was doing and since they where both American college professors they laughed and said “Oh, that is D&D” and they bought me an early boxed set. That sustained us for a long time…
After that: trips to used book stores in Arizona and New Mexico which produced dozens of gaming boxes and books… that often where missing a minor detail such as the actual rule book in the case of Marvel Universe RPG where I looked at the characters stats and built a game around it. I did a lot of homebrews, some ripoffs based on stuff I saw in catalogues or later online that looked cool and eventually my own “universal” system that I have not played with in years but that I’ll publish online if I’m bored one day. As for quick “one off” games… man we played a lot of risk which eventually became “drunk risk” once we turned 18.
How about you?