That day when I destroyed the hard drive of my mother's PC when I was 12 years old. (The drive wasn't properly screwed in the case, and so after a few repositions of the case, it would one day start up sounding like a jet engine and after that scary sound: silence.

My mother took it relatively well, mostly because she saw how I was beating myself up over it. I was so mad at myself as I knew better! I knew how to create a backup strategy, I'm theory. I never really put in into practice though.

She had no backups of course. No way of regaining her data.

Now she does. And now she regularly calls me to initialize a backup of her current data on her external drive. (And every few months I sync her data over to my place on a data storage just in case she loses both her PC and external drive in a fire.)