Typewriters can't stage changes to a document. There are no tryouts, no ways to simulate what a document would look like with a change while not actually changing it. It's a limitation so mild you'd forgive someone from 1,000 years ago for thinking it would be logically impossible. You could make a modified copy, of course, but if all copies are done by hand, obviously no two documents are completely alike anyway.
Of course, computers are able to do things in their own strange way, and saving a file is perhaps the most salient departure from human norms. Most modern tools (including the one I'm using to write this) automatically save, papering over the disconnect between writing and recording. Some tools do this better than others, but it's never been a totally secure editing process.
Both myself and a friend have recently had more than an hour lost to work that went unsaved. Mine was in a program for specialty file formats, and they lost hours of translation work. So I think it's fair to say, whatever autosaving exists in the world, there isn't quite enough of it.
I like taking a moment, whenever I bump into this type of thing, to appreciate the opportunity to enhance my personal zen. Maybe I can even do the work better this time?
I'm not the first person to notice that technology is eliminating more and more opportunities to cultivate forbearance, calm, acceptance, and boredom. It's not a surprise – we learn from challenges, but ultimately would rather spare others the burden. The old heroic tales of someone going off to fight some battle, making sure those he leaves behind never have to face such a horror, they're still relevant. All that happened is, it started working.
All of the big dangers were confronted, and we were safe. And fed, and educated, and that's when the wins really started stacking up. There's hardly any true challenge left in the world – thank goodness! But I suspect that has a strange cost to our character. Cultivating virtues is no longer the default choice. Even the virtue of always seeking to do better and rejecting an obvious default is not encouraged! Well, the world is safer than ever, and we all ought to try to break our bounds every once in a while.
And when we have a few hours' work swept aside, let's be thankful it wasn't years of work. Let's smile, and do the work again, better. The world could have taken terribly important things from us. Perhaps, if we're better, life will take less from the people that come after us. They'll have better tools, after all – the ones we make, when we're remembering those moments that made us who we are.