Man Same here. Mostly the pet thing. I once lost a beautiful piece of art I was drawing to cat vomit and another time a cat just ate it then there was a time my dog peed on my art work. And then with digital art my cat once knocked water onto my computer and kaput it was down for the count. Pets can be so brutal to art! TT^TT
On another note one time my hard drive just died while i was working on stuff. MY computer had problems before so I got use to backing stuff up and saving it like every two seconds but the hard drive died right when I was trying to back up a piece of art 9and homework) and boom they were lost and the backup versions were so curropted that they were unusable. Man i cried for like two hours straight because of that. I am so lucky my dad is "a freaking genius" because he got the computer to turn on long enough for me to copy the files but that was like my saddest experience with losing some of my work. (even though in the end nothing was lost XD;;; )