When you are in school, you think that you will be friends forever with your best friend. Everything is great and you are both or all happy.
Life happens though, and sometimes friends drift apart, never to talk again. If they do talk, they become more of an aquaintance, than a friend.
Sometimes though, those friendships do last. I have had a friend for 20 years now, and I am happy to say that we talk and hang out all the time.
When you are young, you think that friends will always be there and that you need a bunch, when you grow up though, you realize, quality is always better than quantity.
Set yourself up for the best life possible, don't hold yourself back just because a friend is going on a different path. Love yourself always!