It's hard to be creative when you're a bundle of nerves.
Having fun in a social setting means adopting a playful, confident attitude. When you're playful and confident, you're more creative. When you're nervous, that playfulness, confidence, and creativity are stifled and suffocated.
Generally, I think you also need good will toward those around you. This pairs hand in hand with playfulness.
Every successful social encounter I've ever had has been determined by whether or not I was nervous. In the relaxed scenario, I am barely thinking. Thoughts just come to me as if by intuition. And I generally tend to get a positive reaction. My demeanor is relaxed, I smile easily, my words flow like a steady river. My inflections are wave-like and not constant. I get creative. I become funny. I become this confident entity that people actually like.
I don't know who that is.
I suppose I never feel "challenged" by others when I am flowing in this state of confidence. I can be easily thrown in this state, if I feel like a challenge is coming, or it has already arrived.
Nervousness in social situations can come on internally through insecurities. It can also come externally from people I do not like (AKA people who have decided to live their lives as assholes), people that rudely challenge me in a variety of ways, for apparently no good reason, paired with my own constant, buzzing internal turmoil and lack of self-respect.
Maybe I need to learn how to deal with people I perceive to be better than me. Are they smarter, better looking, more funny, stronger, more charismatic, more knowledgable? Their default state of being challenges every fiber of my own being. How can I accept these people when they threaten my own confidence?
Maybe I simply need to learn how to handle challenges. I am afraid of being made a fool, of being proven wrong, of being ridiculed for who I am, of being trounced on either intellectually or physically, of being beaten, to put it simply. Other people try me, and I can't handle it.
"What if they treat me badly?"
"What if people laugh at my expense, because I was treated badly?"
"How can I stand up for myself?"
"How can I even the playing field if someone decides to be mean to me?"
"Do I need to manifest physicality, or actually get physical, or is a battle of wits all that is required?"
"Am I being too sensitive and simply reading people's intentions wrong?"