I nearly lost everything I was working on last night - intricately woven argumentative connective tissue, new relationships between concepts established... oh it was a nightmare. When Word folded up in half, burst into flames, and the ashes blew away, I rolled my chair slowwwwly backwards from the keyboard, and told Jerad that I would have to leave while he looked at it. Which meant that I would have to go sit gently somewhere else in the apartment, and feel moderately ill. I was saving as I worked, but the file was gone (gone!), and it took Jerad* some time to recover the last saved version. I have no idea why this happened, but it did inspire me to immediately source a removable hard-drive, stat.
I've heard of this happening to other people, and I always thought to myself "Oh, if you just saved your work continually, this wort of thing wouldn't happen". Pssht. I have officially been humbled.