The Waiting

So the "special" date was March 17. It was circled 4 times in my planer and about any other place where a calendar was posted. It marked the date when I would get the confirmation on wether or not I had been accepted in one of the most prestigious private high schools in the nation. I had finally convinced myself that the anticipation was eating me alive and it was only righteous to accept any answer that I got back. Unfortunately, nothing happened to my advantage and at this point a rejection would have been fine. I was put on the waiting list. And I thought I had already been waiting. Please Help.

So I ask of you all to help me configure this out. "What exactly is a Waiting List? How many students of the 100 admitted would accept the space offered? Are my chances good? and Should I stay optimistic?