For a couple of years, I had a recurring dream that my older sister (to whom I have always been very close) was being terribly mean and abusive to me. She would call and I would tell her about it. We shrugged and said we could'nt figure it out. About a year later, she started having the same dream about me. One day we talked about it trying to figure it out. We went over our relationship from childhood to the present to see if we had any underlying resentments but to no avail. But they stopped when we started talking about them.
About 8 months ago, I started having recurring dreams that we were teens again living with our mom and dad. My mom disappears and is leading this secret life. she won't call or give us a way to reach her. I was devastated and frustrated and I would wake up very sad and agitated (she died several years ago by the way so it was puzzling). So I told my sister about it and she said she was having the same dream. She woke up mad, and I woke up sad. The more I dreamed it the more depressed I became. Again, having a long talk with my sister about it and they stopped almost completely. Strange isn't it.