Are you aware of the Akashic records? There is the concept that there is a unified field of memories of everyone and everything and that this is what people tap into when they retrieve memories of past lives. However this field is also accessible by anyone and I do think that sometimes we tap into this field when we sleep. Not always but sometimes. I have found in my research that a lot of people have dream of certain places they always seem to visit in dreams almost as if these are real places. I also know a lot of people will seem to be meeting the same people in their dreams even though they have never met them-but they seem so real. I believe this is because they have tapped into the field I alluded to and indeed these places are real and exist. Your dream could be this-but as I say not all dreams are tapping into this field-and only experienced meditators are able to do this with controlled precision-and so they are able to recognise when their dreams are just dreams and when dreams are the drawing of memories from the universal memory field. It is possible to come to some form of understanding about your dream but it would involve a deeper analysis of yourself and your current life. Hope that explains a little!