Old Friends

I have a friend that I used to be very, very close to.  We haven't lived anywhere near each other for years and years, but we used to email regularly and talk on the phone as well, sometimes even once a week for quite a while at a time.  But for a while now, we've been growing apart.  It pains me.  Why?  I think it may be because of my memories of what we used to have, not what we have now.  We have stopped emailing and calling regularly; we called each other, and I heard her voice today, for the first time in probably months.  Looking back, I think it is something that has been developing for a long time, really.  Long talks about shared interests used to open up talks about other, more personal topics; now, we have lost some of our shared interests, developed new ones, or feel less strongly about the things we used to talk about together.  We have less time to devote to our friendship.  The problem of shared interests, I feel, is the biggest; I've gotten so used to being around people who understand at least some of my interests, who feel the same way about them or are at least willing to accept my interests without judging, that I suddenly am not sure how to deal with this friend, who does not, I think, understand some of my newer interests.  Or maybe it's my perception that she doesn't understand that is the problem.  I don't know.  I wish our friendship could go back to the way it was, but at the same time I'm not sure if I want to befriend the person she's become, as the person that I've become.