Growing up in late 70's and early 80's I was around for the arcade boom... mainly played arcades when young but I'm sure I played a few pinball machines too... just didn't know much about them nor care really.
But that all changed in college. My dorm had a pinball machine in it (Hook) and for a poor college student it was cheap... and I quickly learned you could earn free games (something I really didn't know about). This game me a sense of accomplishment while I was having fun and made it even cheaper. It also helped that the score required for winning a replay wasn't too high...
This essentially started my obsession as I searched out more pinball machines to play... learned more about rules... and since the web was brand new I started searching for resources that would help me get better... the pinball archive and rec.games.pinball came to the rescue and the rest is history.