See, this is pretty tricky for me to answer, cos I had read various things on the site and in the forums months before I joined. But that was just part of ordinary Internet browsing. Like how you google something, get a link to wikipedia, and then spend the next hour clicking things like a madperson.
However, I guess I properly DISCOVERED the site a year ago... Yeah, yeah, cliche... Was introduced to ZP, yadda yadda. However, I joined just hours after seeing my first ZP video, because I only watched the ones that pertained to games I was interested in at the time. I figured I'd binge-watch them, and then leave. Much like how i'll read a webcomic trough to its end, and then never look at it again. Or maybe just look back at a particular issue once or twice, years later.
Ah, but then, while watching an episode, I spotted something magical! The "latest posts" box. And one of the topics listed pertained to the first part of the special Red Dwarf episode/miniseries/thingy that I'd just watched. And I felt I had to post. I then began to browse, Reading all about the stuff that was going on in peoples' heads.