Or, to put it another way, you didn’t.
However, spam mail doing the rounds wants you to think otherwise.
“You have three lost messages on Facebook, to recover the messages please follow the link below.”
The links just go to the usual advert / viagra junk. What’s kind of funny here is that an older version of this campaign claimed you were missing one message. Obviously the spammers decided to up the ante so now you have a whole three messages lost to the void.
If you were really that worried about losing your Facebook messages, I suppose you could just have copies of them all sent to your mailbox. At the very least, hover over the links included in these emails – you’ll see that they take you to places that most definitely are not the official Facebook website.
Coming soon: “You have six lost messages on Facebook…”