For me it was songs... Hundreds of it lost couple of years back.... More than 10 years worth. I was converting songs and used select all, delete on the wrong folder. Blasted windows deleted a little from each sub folder so all my songs are essentially gone when I noticed error at 60% deleted.
I feel your grief... I lost all my MMD model files and other files that cannot be found anymore(unless you buy from someone who has it). That was a sad reminder for me to get a back-up
well, your computer expert father should've set you up with a backup in this case... after I wiped all of my data by accident, I have two backups
I download and format at least twice a year. All my downloads come and go, and I rarely miss em. If I do want certain stuff kept, I keep it in my personal drive.
Don't worry, that's mean you can fill it with the new data thing you always want (the new shiny thing like your "my precious"), and this is still better than actually losing your computer Let me guess your rare manga start with letter "H" and same with your dj
*pats* Condolences... My computer started doing weird things a month ago. I freaked out and backed up everything I could fit onto a thumb drive. The whole time I was transferring things I expected it to suddenly break and I'd lose everything not yet transferred. Luckily whatever was wrong stopped. Might have been a virus. I scanned several times, but the thing I use doesn't always tell me if it found something, just silently deletes it.