I have been posting to this blog for quite a few years now about the importance of backing up your files. We’ve even offered entire workshops on backing your files up. There are all sorts of ways you can lose them: dropping your laptop, a lightning strike, theft, flood, fire, water damage, sabotage, and more.
I always tell people they should have AT LEAST two copies of their important files (preferably not stored in the same physical location). The “at least” is important, because sometimes a single backup can fail. Case in point, check out this short animated video of Pixar’s Oren Jacob and Galyn Susman telling the story of how Pixar almost lost all of Toy Story 2 thanks to 4 keyboard strokes and a bad backup.