The End of an Era.

The end of an era. What does that really mean? The web definition is: An Age. A Specific gap of time which ends due to a dramatic or extraordinary change.
I've just finished a two year course and it's quite emotional really. It's not just about the work, but there are people that I've become close to and along these two years we've drifted apart. I dont know how or why it happened, but if I could fix it I would.
I know that this had nothing to do with my work but I cant help feeling that there's too much ending at once and I'm not ready for this era to end.