Here's mine. So I was in the post game of Pearl when I decided to after Regigigas. I needed the other regigis so I went back into my copy of Ruby and a sheet of paper with braille decoded on it.
Anyway I got 2 of the regigis and after each one save the game. I was doing good until I got to the third one (regice). Where I accidently kill him and me not thinking, instead of resting I proceed to SAVE the game only realizing mid save what I have done.
TL;DR
Saving is a good habit to get into but make sure you know what you're saving before you do or you'll end up like me and mis a legendary.
by backofthebill