Many years ago I watched someone stuff the DVDRW (remember them?) which contained all his stuff into a work PC’s pioneer slot loader drive to get some music off it. We stood there and the drive went bzzt, clang, bzzt, clang then sped up way faster than it was supposed to go. This was followed by a large bang and bits of DVDRW coming flying out and then a crunching noise.

From this I learned about single points of failure.

Edit: also in the decade and a half since I learned that you should never trust a magic box, magic piece of software or magic container file system for backups. A plain file system you can just copy your shit back from is the closest thing to a guarantee. Also it’s cheaper to curate your data carefully than end up with 4TiB of crap you’re too scared to deal with on your hands.