While playing Final Fantasy Tatics A2 the main character has a book that writes in itself after every major event...well...I assumed this was an auto-save feature and didn't bother saving, I'm about 20 hours in and decide maybe I should turn off my ds instead of keeping it in sleep mode. go to play, it's all gone.
Aw s#*!
I was so pissed I didn't play it for about 6 months or more. I just picked it back up 2 weeks ago.