I'll admit upfront I'm a bit of pack-rat, physically and digitally, and have CDs and DVDs or lots of stuff (not all of it porn, honest), as well as a nice filing cabinet with older line-art. I (mostly) know where everything is...
Given my art for the last decade or so has been all digitally colored, this meant I relied on these to store much of my finished art along with the websites I originally posted them to. I move and consolidate stuff to DVD every so often, but not often enough it seems and I've apparently lost quite a few things. When did I realize I lost it, oh just when I thought it'd be nice to re-post it. I'm still interested in re-posting some stuff, so I've had to recreate them from line-art and recolor them anew.
It's not just a ploy to get around my inhibitions about posting older work in main gallery rather than in scraps which is my norm, honest.