This is a long period of time to reflect on now. ^_^; Way back in ye olden dayes of the late 90s, I was in middle school (about 12-13), and I got a PC game called Creatures 2. The game had a website, the website had a forum, and the forum had fanfiction. Inspired by the cool stories on the site, I started one of my own, but I never finished it.
I first published a fanfic in the early 2000s, on the Farscape fansite FaDoP (Friends and Defenders of Pilot) and later on Fanfiction.net. I think I even found out about FF.net via FaDoP. I know someone on there was the one to introduce me to the term "Mary Sue," because the OC in that fic is borderline at the least, haha. At the time I didn't quite realize it was something to be avoided, though.
On FF.net, I discovered OFUM, and OFUM led me to the PPC c. June 2003 (at which time I finished high school and then turned 18). It was a few years before I got up the nerve to write a proper PPC story on my own, but I got involved in co-writes (only one of which ever saw the light of day), joined the early archival effort, role-played with my characters, practiced with Fill the Plothole, and eventually got there.
I've typically been more into RP than fanfiction, at least in terms of time spent on it, so it's not surprising to me that I've written more stories for the PPC than any other fandom, or that a bunch of those stories are co-writes. The feeling of collaboration—inhabiting a shared reality, bouncing my bit off the other person's bit, with a goal in mind and/or just to see how it goes—is what I like best.
Apart from the PPC, the only fanfics I've written recently were inspired by Skyrim gameplay, which I guess is me "collaborating" with the game.
As for how it's influenced my life... I admit, I sometimes wonder if I'd have written an original novel by now if I hadn't found fanfiction, but given my track record, I doubt it. Long-term goal-setting and sustained effort are not my strong suits; neither is the sort of confidence in my own ideas that survives very long past the "wouldn't it be cool if" phase.
And of course, recent years have not been good for anyone's mental health, which is not good for creativity. (I am pleased to say I'm better this month than I have been for quite a while. Blog editing didn't work out despite seeming perfect on paper, which is disappointing, but now I'm a pet-sitter and way, way happier. Even an introvert needs to go outside and interact with people more than never! Plus, you know, adorable cats and dogs. ^_^ )
However! I got my first good job through a connection I made in the PPC. I've met lots of people I count as friends here, and would still even if we haven't spoken in years. (E.g., Araeph let me crash on her couch when I was passing through her city last summer, and I let most of a Gathering crash in my apartment!) I've read books and watched shows I might never have considered, because PPCers were into them. I've learned so much about other people, other cultures, and other parts of the world through my PPC connections, and I'm certainly a better person for it.
All in all, my only regret (if you can call it that) is that I haven't been able to write everything I wanted to write precisely when I wanted to because I've had to make sacrifices to "Real Life," whatever the frell that means. ^_~
P.S. I started reading Gloaming right after I got it, but got derailed before I finished it. >.> I'll give it another go once I've forgotten enough to appreciate it again!