It was June, 2003 for me. I'd never heard of Civilization at the time, and was 14. I was at CompUSA with my dad looking for a new game for the summer. I'd been planning to get Age of Mythology, but its video card requirements were slightly higher than what our computer supported (16 MB VRAM instead of 8 MB... bummer). So I looked around some more and saw Civilization III, the vanilla version. It looked really interesting. I wasn't a big history student then (my first really good history teacher was that autumn), but the concept and game both sounded fun, and the game would run on our computer, so into the cart it went! $30 at the time.
Unfortunately, it didn't actually run on our computer at the time. My guess now is it was outdated drivers - the game started up fine, but anytime you saw a city on the screen, it crashed (whether it was yours or someone else's). So I could explore, but that was it - and then only until I encountered an enemy city. Kind of disappointing.
Fortunately, my dad had known our computer was getting long in the tooth for a year or so, and it was over 4 years old then, so he decided it was as good a time as any to get a new one. The next weekend we went out to Circuit City and bought a new desktop. Fast, 512 MB of memory, and 128 MB of video memory - if we'd already bought that the week before, I probably would have bought Age of Mythology. Who knows if I'd have ever tried Civ?
Unfortunately, the setup at home didn't go so well. A scanner not working with Windows XP and causing infinite reboots was minor enough, but Partition Magic managed to mess up the entire partition table (my dad had always divided up the hard drive into OS/Programs/Data before), and HP conveniently put the backup of Windows on the hard drive rather than on CDs. So now we had a nice, shiny, fast computer with no operating system. My dad called HP and they send out some disks, but it would take a week for them to arrive.
So I spent much of the next week reading Civ3's 300 page manual. I read pretty much the whole thing, although I did skip some of the later units' statistics so I'd have something to discover as I played. What I could garner from the manual and what little our old computer could play told me this would be a really fun game.
Finally the discs arrived, XP was re-installed, Civ was installed, and I was able to play it! I played Earth (Huge).bic as the Americans first, and played most of the day, until by mid-afternoon I realized victory was beyond hope and saved the game. I still have the save, and a couple years later reloaded it and managed to pull back to a somewhat competitive state by 2200 AD or so. But it wasn't long before I was playing another game, and doing a little better, and Civ quickly became the game of the summer.