I'm guilty of this.Ando85 said:little brothers overwrite your save files.
A few years ago, I ACCIDENTALLY deleted my brother's FFX save file. Over a hundred hours, all aeons, celestial weapons, Al Bhed letter spheres all gone into the Ether. I've never forgiven myself, even though my brother has.
As for most devastating save loss for me, a little while ago, my PS3 had to be traded in because it was overheating in ten minutes. No biggie, until it came time to transfer my data to my laptop for safekeeping. For whatever blisteringly idiotic reasons, a few saves have copy protection, meaning they cannot be copied to anything other than the cloud thing available to PS Plus subscribers only. This wasn't a big deal, other than one save. Dark Souls. Let's just say that, over 300 hours split across 8 characters, I was really upset.