1. What happens to you personally?
2. What are some experiences?
3. What causes you to need to "recharge?"
1. The most noticeable thing, to me anyway, is my thought process. In addition to losing focus and energy, all of my "remaining mental (and physical, to a slightly lesser degree) energy" goes straight to planning how I can "get away".
2. Primary experiences are strikingly similar to yours, but perhaps even more so. I consider myself to be highly introverted, or at the least, significantly more so than the people I am around on a weekly basis.
You said:
* General lack of energy and focus
* Losing patience with people and things in general much, much quicker than normal
* A general lack of tact
* Wanting to sit around in silence with just my pets or music as external things going on, or to just play video games all day
I say:
Yes, I lose energy and focus. In this case, it's like I said above.... I can no longer keep focus (well, I can force myself to, but it makes it worse in the end. It's like using a credit card to pay for a credit card bill.) and it becomes very hard for me to concentrate. (Not so much simple tasks, but anything worthwhile. In my book, that requires thought.)
Yes, I definitely lose patience with people and things. I don't ever "get mad", in the sense that most people do (emotional outburst, etc, etc) but I become very blunt, very cynical, and very irritated in general. It's usually a build up of "little annoyances" that get me to this point. (Which can be anything from overly-extroverted people that won't quit talking, somebody screwing up something I set up or planned, or just stupid things, like I couldn't focus enough to get my tie on correctly or whatever.)
The general lack of tact ties into my last statement. When I get to that cynical, blunt stage, it's just that. I normally take a small amount of consideration to other people and their feelings when I make statements, but when I am in this condition, I don't care at all. I speak very plain, simple, and to the point. Usually negative. ; )
Now here's the extreme part for me, I think. When I get to that point, all I can think about is escape. I think about being alone (doing my "introvert" stuff, like reading/gaming/writing/more reading/listening to and playing music/etc) almost as much as a teenager thinks about sexual intercourse. It's they way I would imagine an addiction would be like.
3. I think I answered this one with above statements. Basically, the need to recharge comes from....too much stimulation, in the form of....almost anything but self-acquired information. I never get tired of researching things, reading stuff, or learning. The number one draining thing on me is social interaction. I know that sounds....stereotypical, but it's true for me. I read somewhere (probably on here, if I recall) about introverts having to put more thought work into conversations than extroverts. I don't know how true that is, but when in conversation, I spend a few seconds more than most people do to respond, because I'm.....really thinking about what they said. Unless the answer requires a quick response, I usually think about it for a moment.
After a while, that starts to grate at me. I can easily digest information I feed to myself, because I can "ingest" it at my own pace. But with some people.....it's just too fast. It's sort of like trying to stream something or download a file on a dial-up connection. That's probably a decent depiction of how my brain works.... Imagine a massive hard drive, great processor, just all-around good computer, but connected to the outside with *ugh* dial-up.
The beauty of it....? If I succeed in getting my introvert time, I return to my normal, stoic self. Plain on the outside, perfectly fine on the inside.
....until that battery runs out again.