Just recently a colleague had their drive die on them; these things happen, and it wasn’t much of a hassle to reimage a new drive. She’d even backed up her bookmarks, but in this modern age it turns out that’s not good enough. There’s a lot more to the modern browser experience than that; a hoard of passwords you probably don’t remember for sites you occasionally visit, searchable browser history going back months. Your personal Browser State, that Firefox’s clever caching and their extraordinarily useful new toolbar at the top there have made more and more valuable. Your web-browsing experience (right now, believe me) being actively mediated by a handful of ambient-information butlers that you barely notice until they’re gone, not quietly doing their thing in the background on your behalf. Losing all that, or trying to duplicate that experience on another machine, can be a huge pain in whatever orifice you’d pick last. She’s still missing that, and it pains me to watch that happen.
It doesn’t have to be like that, though. Have you heard of Weave? I don’t think a lot of people have, but it’s really slick: it will bundle up your browser state in a neat little package and back it all up to a server at Mozilla (though you can set up your own if you like) and when your machine goes sideways or if you just start using a different one and want your past back, there it is.
It’s all nice and cross-platform too; browser state is about half of my working environment now, so getting my new Mini set up just so was pretty much painless. You need a current-ish version of Firefox to make it work, but you should have that anyway. Take the time to set it up, it’s absolutely worth it.