Believe it or not, years ago I managed to organise an entire class reunion via the phone book (it's a very old concept, younger members won't know about
)
It was more successful than I thought it would be, only two out of thirty-two couldn't make it (one was living in Belgium, the other in America!)
I'm not on FB, but I still meet people from years ago whilst going about my daily life. As Joey says, we have all changed (in so many different ways) be prepared!
All I can say about classmates that I found amazing was the few that were hungout to dry as 'no hopers' by the teachers, were in fact the most successful business people. Goes to show that there is hope and teachers do get it wrong!
Good luck with your search