Once, a long time ago, I spent the best part of a night writing a report for college, on an Amstrad PPC640 (http://en.wikipedia.org/wiki/PPC_512).
Once I was finished, I saved the document -- "Save" took around two minutes (which is why I rarely saved).
I had an external monitor that was sitting next to the PC; while the saving operation was under way, I decided I should move the monitor.
The power switch was on top of the machine (unusual design). While moving the monitor I inadvertently touched this switch and turned the PC of... while it was writing the file.
The file was gone, there was no backup, no previous version, nothing.
I had moved the monitor in order to go to bed, but I didn't go to bed that night. I moved the monitor back to where it was, and spent the rest of the night recreating the report, doing frequent backups on floppy disks, with incremental version names.
Yeah; I was lucky that my first experience where I could lose data like that (before it was on punched cards) was a nice UNIX(TM) V6 system on a PDP-11/70 that had user accessible DECTAPEs. Because I found the concept interesting, I bought one tape, played around with it including backing up all my files ... and then I learned the -rf flags to rm ^_^.
That was back in the summer of 1978; today I have an LTO-4 tape drive driven by Bacula and backup the most critical stuff to rsync.net, the latter of which saved my email archive when the Joplin tornado roared next to my apartment complex and mostly took out a system I had next to my balcony sliding glass doors and the disks in another room with my BackupPC backups.
As long as we're talking about screwups, my ... favorite was typing kill % 1, not kill %1, as root, on the main system the EECS department was transitioning to (that kills the initializer "init", from which all child processes are forked). Fortunately it wasn't under really serious heavy use yet, but it was embarrassing.
Once I was finished, I saved the document -- "Save" took around two minutes (which is why I rarely saved).
I had an external monitor that was sitting next to the PC; while the saving operation was under way, I decided I should move the monitor.
The power switch was on top of the machine (unusual design). While moving the monitor I inadvertently touched this switch and turned the PC of... while it was writing the file.
The file was gone, there was no backup, no previous version, nothing.
I had moved the monitor in order to go to bed, but I didn't go to bed that night. I moved the monitor back to where it was, and spent the rest of the night recreating the report, doing frequent backups on floppy disks, with incremental version names.
This was in 1989. I've never lost a file since.