Yeah, I know what you mean about finding yourself more and more isolated as time goes by.
I think someone already touched on it in this thread, that when you get into your thirties, people's lives change; they get married, kids, move away for work etc.
I used to worry about staying in touch with my friends. Then there grew a realisation that they were putting themselves and family first (naturally).
It was this that made my decision to up sticks and move away much easier.