How to Build Relationships

All of the literature I have been reading about missionary fundraising has talked about establishing relationships.  That the emotional support is more important than the financial support.  That as long as you have surrounded yourself with a group of fabulous, interested Christians you will be successful.  With that in mind, I have been reflecting on the relationships in my life.  Ever since I have started becoming more involved in church and mission work, there are certain relationships in my life that have disintegrated.  Then there are other relationships that are just not being nurtured.  Sadly, I realized that most of the relationships that I am not carefully cultivating are the ones with my own family.  Why is it that sometimes it is hardest to keep up with, and even make conversation with your own flesh and blood?  That is one of my more recent goals: to be better acquainted with my own family.  Why is it that I can have no communication with my sister for months and be OK  yet be frustrated with my boyfriend over a couple hours of no contact?  It doesn't quite make sense.