I think you're stretching it a little far, but at the same time, you're more correct than you are wrong. Graduating high school and leaving behind hundreds of familiar faces is just a thing of life. I'm a junior in college now, and going from high school to college was the biggest dividing line in my life. Once students graduate and leave their houses to be on their own, it really brings out the real person in them over the next few years. That said, everybody matures on their own and at their own pace, and goes their own seperate ways. What I'm leading up to is that out of the 100-200 people that I at least said 'hi' to in the halls, or who were friends, I stay in touch with maybe 10 of them to this day... no more than 5 on a regular basis, and they're not even the ones that I would have called my best friends either back then. Life's funny.
Get your good friends on AIM or your preferred chat client- it's an invaluable program for this time in your life, and be upbeat. It's just time for another leap of considerable distance in your life, and we all did it. On the bright side, ever since I left high school and that 'previous life', I've been a better person, matured even more, and am having the best time of my life, with arguably even better people than I knew in high school. Congratulations on your graudation- it's still a big stepping stone in life. Now you can start planning your sucessess and plot revenge for the reunion on all the people that gave you crap in high school! Well, at least that's what I'm doing...
Enjoy.