I have a billion back ups of my projects lol. Even when working in one sitting. Before I make any major changes or additions I'll do a quick backup save in case I break something.
Also, one time I was working in Photoshop and hadn't saved in a while. Then the power flickered (and of course my UPS is garbage and did no good) so I lost my work. I wanted to smash my head on my keyboard lol.

