I have had this problem:
I am nice even to those people who are not nice to me. It goes sometimes even to the point where I get verbally kicked into my face and still I am totally unable to be rude to them.
I basically try to avoid people who are not responding to my friendliness. It's not always possible (at work for example) and that's why I would need to change this "habit" of mine.
I do have to admit that I too have my limits and I will eventually say something when I get fed up. I can be very offensive when I get mad and then people really should watch out their actions concerning me.
The question here is:
Is being friendly to everybody a common NF problem, a common ENFP problem or is it just me trying to behave nicely with people?