The brain of your partner
And when you copy the important brain parts of your partner into your skull, next to the corresponding parts in your own brain, will you finally understand him, or her? You copy the feeling brain parts of your partner next to your own feelings in your brain and connect the new cells to other brain parts just as your own feeling cells are. The two sets of feeling are both provided with a kind of dimmer switch. You can let come up one set at will and let fade out the second, then let the second set slowly come up again, and so on. You can keep the second set as long as you need and then finally let it disappear again. And so, when circumstances require, will become clear how the both of you can adjust their feelings to each other in order to continue the relationship. Then you anyway will have the choice things that started in love not to let end in war.
You can consider to execute this procedure before you enter a relationship that is meant to get children. Would that do?
The cells the copy is made of, might be a tricky one. Suppose you are a male and want to grow in the female feelings of your partner. Maybe the female brain not only differs in structure but in the use of the DNA too. So the cells the copy is made of better be with the female DNA of your partner, especially the X-chromosome. But there might be more on the X-chromosome than just the wanted properties. The most easy way might still be to copy the entire chromosome and then methylize the unwanted genes (which would switch them off) and watch they stay methylized.
Supposed is the female brain parts do not need the female DNA of e.g. neighboring brain parts. The female DNA in the copied brain parts should be sufficient. We will see.
The male will be able to feel how it is to have a baby, in all its details.
And children? When adults live longer - and they certainly will - there are in proportion lesser children. The brain of children grows too fast for their cells to host nanorobots in a useful way. However, I guess autism and psychosis will be steered within appropriate borders, already in the youth. I presume that on the average children will be left alone. They will be able to enjoy their whole youth as they like. But also, children learn so easily that I wouldn't be surprised when they still would learn reading and writing in the natural way.
What are emotions at cell level? We still don't know for sure. Usually accepted is that there is a distinct brain part for fear, and another part for rage, one for grief and another for happiness, and so on. Next to that my guess is that there is a kind of decider, that decides when to activate what emotional brain part. The decider uses this and that recognized situation to incite precisely that stimulus of those emotional brain parts, and at what rate and how long. I guess that part is what we call the personality. Memories can constitute a recognizable situation that by the decider is connected to a certain emotion. The decider possibly is no more than a kind of program that prescribes precisely when to activate what emotion.
The decider may be a separate brain part too or a kind of network pervading the emotional brain parts. The program even can be an epigenetic mantle around the DNA, when should turn out that emotions are directly incited by gene activity (activating this gene causes that emotional brain part activity). There are signs that epigenetic imprint is heritable over another two generations (stretching over three generations all together). Maybe all possibilities work, each at it specific place. Your soul might be a set of programs.
If so then, in the emotional brain part copying process, it might not suffice to copy only the emotional brain parts. One has to copy the decider too.
Are properties like reliability and confidence in a brain part? Can it be copied? Honesty, enthusiasm for your work, conscientiousness and the ability to enjoy the morning when a new day has begun? The ability to be happy in the circumstances you have chosen? Let's suppose it can be done.
Nowadays people cannot trust each other. But they do trust each other's money.
Suppose you can read each other's mind, you can read each other's feelings and you can adjust your feelings to each other when circumstances require. When this kind of adaptions are made, you can trust each other instead of the money.
Suppose you let grow in the ability to enjoy the morning when a new day has begun, and enthusiasm to do your work, and all the necessary knowledge and skills needed for your job. For you it will be easy to do your job. People around you will trust you in your job. When all just do their jobs and none cares about the money, in principle the group will function pretty well without money. I don't say money will entirely disappear, but it will loose importance and the financial sector will shrink. When circumstances require, they can do without.