Yeah, I do that stupid thing all the time. Not usually on important stuff...usually it's when I'm playing with things to set up a new scene. I don't want to save it, because I'm not sure I really want to do the scene that way...but I still spend 20 minutes getting the pose and everything right...then I go to delete one of the props, and accidentally delete the main character. Of course, saving into a temporary file would be good, but then I get a ton of temporary files lying around that I don't remember what they are. Sometimes you can't win for losing :-)