It has happened to me and my wife as well. Being close together and working towards the goals that we both have agreed made some friends stay away. In my case some friends are way to afraid of commitment to a person and so they are afraid that my decision is not compatible with friendship and I've wondered why. My wife has also asked me why were kind of lost our lost friends and I have replied that life has different stages and we are just in a different stage or maybe we 'leveled up' and some people stood there in the last level or stage. The great thing is that you can discover which of your friends and family will stay close to you on each level and no matter what you will and can count with them. Maybe some friends will catch up later in some other stage, who knows?