I too have had friends that stopped growing at a certain stage of their lives. We stopped sharing things in common. I had to move on to spending my major time with new friends that I had more in common with.
Sometimes I'll still see them on rare occasion and it's good. It's fun to talk about the old days. But in small doses. Alot of people get stuck at a certain point and never move beyond it.
Warning...here's my post on the subject:
Don't be like Uncle Rico.
So although it's tough, some of these friendship changes are necessary in order for you to grow and be happy.