Totally get that 'losing files once was enough' feeling. I had a drive die on me years ago and lost all my photos. Now I'm paranoid about backups. I use cloud storage and an external drive, just in case. It's not worth the risk to have only one copy. Once you go through that, you never skip backups again.
Ever think about how old the physical drive itself is? Even with cloud backups like Anthony618 said, the hardware still ages out quietly. I've seen drives just give up from sitting around too long.