A fantastic talk on consciousness / perceived "reality" -- an explanation as to why wars happen, why you can't see eye to eye with some people, why sometimes relationships don't work no matter how hard you try.
I've often talked about this as living in different realities, a 2-D reality, a 3-D reality and so on. It would be hard for a person living in a 2-D reality to understand someone living in a 3-D reality. However, the person living in a 3-D reality easily understands someone living in a 2-D reality.
This is evident, of course in families, but more painfully in romantic relationships.
Another way of saying it is that you don't share the same world view. When you look out at the world, you asses things and see them differently from your partner.
For a relationships to work, usually you need the two people to live in the same perceived reality. Then you can work out disagreements.
You can't work out realities.
In this talk, Caroline Myss makes this very clear.