The need for privacy is a fundamental physiological need like social contact, hunger, thirst or sex.
All organisms need downtime, the time out from a normal schedule to relax.
Usually, the greater the stimulation by others, the greater the need for privacy.
Continuous stimulation - parties proceed by meetings, followed by family gatherings - produces a need for solitude to compensate.
Continuous stimulation is like forcing yourself to eat a big meal right after you have just finished one.
In a family situation where the need for privacy is not accepted and the need for downtime is equated with rejection, people often wind up playing psychological warfare and fighting.
This gives them sulking time.
Which is a negative form of privacy.
At different times in your life, you may find you need different levels of stimulation and privacy, depending on how satisfied or frustrated you are.
Sometimes you need more alone time to think things out, to assimilate or to be blank..
Physiologically, some people have a high need for stimulation.
Others can't tolerate a high level of stimulation without time to digest it.
Be aware of your own time...
Structure your needs.
Reason: Meeting these needs will help you conserve your psychic energy.
Situation: both spouse work.
After work.
Each spouse needs some private time to be alone and unwind.
If each recognizes it as a valid need, they can each nap, shower or read the paper.
Later, when refreshed, they can get together for some satisfying qualitative time...
If the married couple is out of sync (one needs some qualitative time while the other needs privacy), recognize the difference.
You'll be better able to manage stimulation and privacy and negotiate what you need with the people around you.
Possibly, for the first hour, one can ignore the other while privately reviewing the day's stimulation.
Result: More emery and an eagerness for the time that remains.
Both win.
If they don't compromise, the result will be fights to get the downtime they need.