Because, while I was out this morning, my main system had a BAD crash. Almost everything on my desktop was gone. All my programs "didn't know me" (including Thunderbird, which I think has lost all my old mail). I probably lost 300-400 tabs in FireFox and all my bookmarks (well, I had backed that file up a few years back). This really sucks.
Fortunately, I just (a few weeks back) installed a new external HD that I had sitting around (waiting to use it for a data retrieval project from a previous dead drive), and had backed up most of my files ... unfortunately, this did not include the program files, which would have had my FireFox and Thunderbird data ... so I was able to re-construct my desktop for the most part. I was disturbed to find that my CrashPlan back-up-to-the-cloud system didn't appear to be uploading those program files either ... so they look to be well and truly gone.
I've been in such a panic/funk about other stuff of late, that I really, really don't need this (see the "friends only" posts). Sucks to be me.