In 1984, I bought my first PC - the Commodore 64 - because Sublogic had just released a version of Microsoft Flight Simulator for it. Up to that point, I'd been limited to playing a Star-Trek port on a local University's mainframe - when I could wrangle a friend who worked in the data center out of some computer time!
I played various offline sims on and off for about a decade, but eventually tired of civilian flight simulators. In 1997 I bought a new computer, and the "Flying Corps" air combat game, but the new system also came with a copy of Interactive Magic's "WarBirds" on one of the demo disks. I played that offline for about a thousand hours (not exaggerating, or if so, at least not too much) over the next 2 years, and then signed up for online play finally in late 1999 or early 2000, after joining a WarBirds-based squadron. I flew WB's for a number of years and thousands of dollars, became active in a Corsair oriented squadron and as one of the original Beta-testers of WarBirds III, but grew disillusioned watching my fellow squadmates growing frustrated with the Jay Littman/Hotseat era of development (and all that that implies) and after the last of my squad stopped flying in WarBirds, I switched to WWIIOL.
I flew there for about a year, and then spent most of another year waiting for some fix for some (any!) of the shortcomings of that environment from an air to air perspective, and finally "gave up" and signed up for Aces High at the end of 2006.
P.S. Old timer and senile to boot - I already posted once and forgot!