I think there are a lot of introverts on this forum!
And I am ready to hang out at an artist's retreat with Peri, rabbit, Irene, Gaylene, Kerry, LisaP, Kiwigal, DianeG, or any others who want to join us non-shy introverts any time! I would gladly listen to your artist or teacher or editor or book and arts industry talks, give one of my own that you might enjoy, visit your studio and talk about your work, examine your creations, listen to your playing, gab like crazy with you on walks or at meals, and then go off to my room where I could be on my own for hours.
Actually, I want to LIVE at an artist's retreat.
To my mind, it is perfect.
In the best ones, you have your own space. A room, a studio (maybe both) and a bathroom that you don't have to share.
And at least some meals are shared. You don't have to go to them, so if you are working hard, you can work through. But if you're at a stuck place or just feel like company, off you go to the meal. Which you do not have to cook. (Even though I enjoy cooking, I love not having to worry about it.)
There are events you can choose to attend or not, and you don't have to feel obligated if you choose not to go, the way we often feel in real life.
You can hike, bike, or otherwise enjoy exercise in the outdoors on your own. Or with others if you prefer.
And the need for time alone or in smaller groups is understood and supported.
This is what introverts find difficult in the regular world. I used to teach high school, and I loved the kids, loved their energy -- but entire days of it drained me. I would go home feeling stressed and jangled. It would take me a while to settle down and I didn't have energy left over for doing much.
Equally, though, at my recent online job, I often missed teamwork and companionship. It is one thing to be alone for my creative work (hugely necessary!!!) and another to be alone all the time for what I consider more mundane work. In that case, I love to work with others.
Yesterday I spoke with a novelist who collaborates with a friend to write her books. I must say, it sounded like incredible fun. They text each other with tons of ideas at the generating stage. Then one of them writes a draft; then they both go over it and edit. And the one who doesn't write first drafts is more of a business person who does the selling.
This is for commercial fiction, though. Not sure how it would work for more literary work.
Gaylene's explanation is best. We're all on a continuum, and many of us train ourselves to exist comfortably enough in a mode that is less natural. But the main criterion is what recharges you -- time alone to reflect, or more time with others? In my case, the reflective time is recharging, and the social time, however deeply enjoyable, is draining. Give me a few minutes on my own and I perk back up and get ready to enjoy my fellow humans again.
ETA, Angie -- I am INFJ and I think quite a few others of us here are, also. I quite far to the I side, very far to the N side, almost equal F and T with a bit more F, and relatively far on the J side.