I am about to use a term that amny today consider close to an obscenity and which is all but meaningless to entire generations.
Discipline.
The lack of discipline which occurs when societies are prosperous and peaceful for too long leads to decadence. Eventually a decadent society is either conquered by a disciplined (or barbarian) society or it collapses into totalitarianism. The current political polarisation signifies decadence - politicians no longerpossess the discipline to put the good of the nation or the people before their personal ideas and ambitions. The barbarians (fundamentalist Islamics such as the Taliban) are on the increase while Trumpian totalitarianism pushes its way into our politics.
Then there is self-discipline. The internalised discipline that prevents us from presenting ourselves differently in different contexts. The refusal to compromise ourselves to others expectations.
This is me. The only me. The me that writes articles and responses on Medium is the same as the one who writes fanfiction, plays video games, takes the grandkids to school and does the wahing up. I do not permit myself to vary from that persona - that truth.