At sixth form, I had three best friends. I only see them occasionally because two of them have moved miles away, and the other one works stupid hours that clash with my stupid hours. I made three close friends at uni, and we meet up as much as possible, but by the time our schedules have a free day at the same time, it works out as once every few months.
So yeah, it is sad the way things work out, but life takes over and other things start to become more important. I am currently in the process of trying very hard to change my working hours so that I can see my friends more, because I just feel as though I never ever see them.