I joined to
vote in Featured Images and
to boost my ego by excessively editing my userspace as well as talking to other users and do anything except edit articles (aside from the early minor Graffiti Runner, Toy Field, Lean Mean Ravine, etc edits). Gradually I became more involved, like maybe two months or so later I got involved with bigger projects and less userspace editing.
Before I joined, I was lurking the site for quite some time. I remember when the site still had "creative" headers for game appearances, like Waluigi's "Dancing His Way To Defeat" being a header for Dance Dance: Revolution: Mario Mix. I remember seeing
one of Dippy's old proposals on the main page, when we used to display proposals on it. I still vaguely remember the old logo being in use, the one with Super Mario All-Stars Mario sprite on grass. So I guess I could say I was technically around since June 2008, just lurking and not knowing what's going on in the community and just using the site like any lurker was using for: information on Mario subjects. The only reason I didn't join until Featured Images rolled around was that I was a bit shy and nervous for contributing and I felt this wiki didn't really need me, but there were some Featured Images I really liked and hated so I just had to vote for them so...eh.
Now, I come back here because I genuinely care about the site. I probably don't have as much consistent vigor I had, as it was before the advent of y'know, mods and stuff, right now could be one of those periods where I slump with the editing, but I come back to it on a near-daily basis because that's how much I care about the wiki.
Well...I rambled on for more than what I wanted....