No matter how funny joke I make, only a few people can catch it and other will even ignore me.
Mostly، an awkward situation or even a 'Hate' will be generated.
No matter how boring and unreasonable other do to people in their circle, A smile and laugh Will always appear in their face.
No matter how good I try to act, it is always bad thing in their eyes.
No matter how worse their mistake, their friends will always consider it as a good thing, or at least showing an understanding.
A connection between people is sure confusing.
Smilling, being kind, and being polite are much easier to be done when meeting a new person than to people I have known.
Frankly, the conversation I do with unknown people feel more comfortable and well.
There are many reasons...
First, those unknown people don't know my weakness nor my problem
Second, I do also still not know both their bad side and rotten intention.
Third, the 'moral & privacy' walls are thicker, the line will not be crossed. If it will, then it is only a pure coincidence for sure.
Forth, the chance of another meeting is close to none. Because of that, We always try to left a good impression.
Fifth, There is almost no burden shared between us.
Sixth, the act of being good and friendly are not too complicated. It don't need many behind-the-scene reasons to do, such as act of pity, make fun of you, and asking their need.
There may be many other reasons, but I can only write this much now.
That are my own reasons and can be different from yours.