

It depends on a number of factors.
How thorough is the isolation/how “high” are the walls? Can I perceive the world outside the walls in any way?
How good is the propaganda?
Do I have anything to lose other than my life? Do I have a community I care about within the city? A family? Children?
When I was a kid public and semi-public pools would have signs that said “welcome to our ool. Notice there is no P in it. Please keep it that way.”
Years later it occurred to me it might make more sense to have a sign that said “welcome to our L. Notice there is no poo in it.” And so on.