Sometime 1986-88. I am in my nurse training and I have to submit a multi-thousand word essay. I type away on my Amstrad CPC6128 which was running Brunword (a dominant wordprocessor at the time). Somehow I hit a keyboard shortcut which highlighted and deleted everything on screen. After staring to the screen for a few minutes I grabbed the manual, ran out of the flat to the local telephone box.
Called the developer - yes, his actual phone number was in the manual.
"Yes, the work will still be in the computer but it is impossible to get it back."
That was the moment I learned that backups are not optional.