I guess I became a fan shortly after Magnolia came out on DVD. This was also around the time I started getting serious about wanting to become a filmmaker, and I came upon Magnolia's IMDB page, and thought this should be one of the DVD's I'd get (as I'd just gotten a DVD player). Just thought it sounded interesting, and I remember my mom talking about it when she'd seen it in the theatre.
So, I watched it, and needless to say, it became my all time favorite movie. So I went back to IMDB and looked up the writer/director... some guy named Paul Thomas Anderson. I was surprised to see that he'd also made Boogie Nights.
I was like, ten years old when Boogie Nights came out, and I remember seeing the trailers/tv spots for it and thinking... AWESOME!! A MOVIE ABOUT THE 70s!!!! (I'm into 60s/70s pop culture) I'm not quite sure if I actually knew what porn was at the time. Anyway, Boogie Nights was added to my DVD wish list, got it and loved it.
Eventually, I became a fanboy, despite never having seen Sydney... then they showed it on IFC, and I awaited the day I was actually able to find the DVD in a store. Hooray, so, I'd seen all of PTA's movies, and was keeping up with the status on PDL. Followed all the Cannes coverage and come October '02 experienced PTA on the big screen for the first time.
Oh, and I eventually did find Sydney on DVD at Borders. Quite recently, actually.