If you don't know anything about Post Secret, you should familiarize yourself.
My mom brought home this book from the Oakville bookcrossing meetup. I've been reading Post Secret regularly online for a while now so I took the book and sat down with it and read it until I came to a point in the book, about half way through, where I recognized the faces of people. The secret reads "I still look at your 3rd grade picture and think what might have happened if I hadn't moved 825 miles away". The picture is a yearbook style picture (double page spread in black and white with a red heart in the bottom left hand corner for all those that read this book after I do).
I immediately recognized 2 faces, then after looking closer, I could pick out about 6 people I recognized. This is the other third grade class from my elementary school! I don't know who sent this in, or who the boy is with the heart around him, but how weird is that!