Not everybody's life.
This is what I was referring to. OBVIOUSLY your high school years count as much as any other year of your past into forming the person you are now (the general "you").
You on the other hand are saying that high school social life is pretty much the same as post-high school social life, which is simply absurd in most cases. Sure if you enroll in a university that all the people you knew in high school enroll in, then obviously, them being the same people, not much is going to change. But that's not because of what high school was like - it's because you're hanging out (or observing, whatever it is you do) with the same people you hung out in high school. Duh.