Goodness, am I glad to have found this thread. I really identify with what Skyward and others (Quay, most recently) have been saying.
I start to become very alienated from reality as well if I have no social contact for a day or so. This rarely happens to me now, however, when it has happened in the past I have felt like my mind was almost floating away into a dream. I could be making myself lunch and be thinking about the most abstract, day-dreamy, symbolical ideas. I think, perhaps, for INFJ's although we enjoy/need time and space... we also need some proximity to other human life to keep us tethered to this planet.
I used to go through extremes like that as well, though they were tied to longer periods of social inactivity. Now I experience what Skyward has been talking about. I do think that those times of "indrawal" are very important for our type. It is not something to put an end to- it is an important part of who we are. But it is incredibly important that we not stay there. What one of you said about going into a period of that kind of introspection and then coming out with the necessary perspective and tools to engage the world around you was so insightful!
Tycho said,
"I'm in a constant state of "epiphany", always thinking that I'm becoming aware of something really important. But if you'd ask me what it is, I'd have a hard time to explain it; because Ni is not about having concrete thoughts, but a way of perceiving the world."
...
"I feel like I'm about to leave such a Ni-dominated period for now (that lasted over 3 months and was triggered by following an intensive master class with an INFJ writer) and I start to have an active desire to contribute things to the world and be a part of it; actually, stronger than ever before, as I'm more aware of what my role in the world can be."
This is exactly my experience! I have just left a similar time period of slightly less duration and have come out of it with the necessary drive, focus, and wisdom to pursue my next tasks with vengeance.
One thing I found out about changing my mood, maybe it's related to an inferior Se, is that I tend to get out of a depression if I just turn into a caffeinated clown for a while... granted it only works if at least a couple people are amused by it. Anyone else who gives me odd looks just amuse ME then. Maybe that's what they mean about giving your inferior function what it wants so everything else can work correctly.
This is very true for me as well. After an intense Ni-dominated period of even a week I feel the need to bow to the Se and create an experience such as you describe. This works very well as it feeds my needs while also connecting with other people and serving them by entertaining them. This almost always results in very positive feedback and strong rapport between us, establishing that connection again and catering to the positive aspects of the whole "mirror" analogy you guys went over.
As I have gotten into the habit of accepting this kind of ebb and flow process, I have come to find that the Ni-dominate times can be of so much use. When used in conjunction with an eventual "coming out" that involves dialogue with the world and a passionate outpouring of self (like Tycho was saying), this process can be the most incredible, fulfilling experience.