There was an Army Ranger deployed to Afghanistan. While he was there he received a letter from his girlfriend. In the letter she explained that she had met some other guy while he had been gone and she wanted to break up AND she wants pictures of herself back.

So the Ranger does what any squared away Ranger would do. He went around to his buddies and collected all the unwanted photos of women he could find.

He then mailed about 25 pictures to his girlfriend with the following note:

I'm sorry, but I can't remember which one you are. Please take the one that belongs to you and send the rest back.