What makes a brain a twin-brain?

Well, science may not back me up - yet - but reading Dr. Barbara Klein's book "Alone in the mirror" started me thinking a bit. There are numerous articles on the web telling you how you might proove (at least to yourself) that you had a twin who died before birth and there are some things always mentioned - changing partners often, unable to be alone, eating disorders - and some things mentioned very rarely or never at all.
Like "instant response". A twin fetus in the womb experiences instant response whenever he kicks his co-twin. It's part of normal existence to get a reaction to your every action. How could it be otherwise since there is no way for human beings to be closer than in the womb.
And here we have a child whose brain developed with a pattern of instant reaction to action born single after the co-twin vanished, was miscarried or stillborn. The brain which developed in this peculiar environment does not magically turn into a brain which underwent a different development only because the co-twin is no longer there, instant response is still a normal feature.
And here we have parents, family, teachers, peers who do not know this child has a twin-brain. They only realize he/her expects an instant response to his/her actions and they say "you're too demanding", "everything isn't about you", "you set too much store by yourself", "he/she is unable to socialize with others, be part of a team, let others have their share, is egotistic" and so on.
The twin-child does not know what's happening because he/she mostly does not know she's a twin herself and if she knows doesn't realize what it means to have a twin-brain. The only thing made clear to this child is: you are wrong. The way you behave is wrong. Your attitude is wrong.
The child ideed is wrong. He's in the wrong world. She never was meant to live in a world without someone to provide instant response. He was made to live in a twin-world, he's a twin.
This may sound like a minor thing, but it isn't. It may ruin a family, send a person to therapy for years with nobody able to really help. It's NORMAL for a twin to expect instant response as it is normal fort a twin to expect nonverbal understanding. It's not normal to expect the singleton world to understand this, but how is the twin-child to know. Since the brain can't be redeveloped the only help I can see, so far, is to remember every time the inevitable disappointment occurs to remember: I have a twin-brain. The other do not NOT respond to me because they don't like me but because they aren't twins.