Read this article on Introverts first: http://www.huffingtonpost.com/2014/11/07/physical-behavior-of-introverts_n_6069438.html
I felt relieved reading this... some of the points made are about things I've always felt somewhat guilty about; I feared I was selfish and a navel-gazer. I don't like trivial small talk. If I ask you how you are, I actually want to know, and if you ask me, it never occurs to me that you don't actually want to know!
I hate answering the phone unless I am actively waiting for a call. The majority of calls I get make me pick up the phone to see who it is, and sigh and mutter "please just leave me alone!" unless it is friends or family. This is why I have come to prefer texting and email; it gives me time to consider my response, which apparently is what I need. In addition, I don't like in-depth phone calls, because I am missing a lot of visual cues that I need to gauge my response. They're fine for a brief exchange of information without all the "How are you?" preludes.
I don't tend to think of myself as being overstimulated when I get stressed out; but the distractions of people in conversation nearby makes me want to tear my hair out sometimes at work. I can't tune them out, and so I feel fragmented, and I can feel my energy draining out of me.
I have no problem being on stage. It's never frightened me, even when I was doing improv. I was mediocre at best, but it never made me nervous. I can stand in front of a group of people and talk to them at any time about anything.
When in a large group setting, like choral singing, or a classroom, I move to the periphery if at all possible. So for me it's not the aisle seat, which is worthless once you're in the air since you can't leave; I pick the window seat. If it's choir practice, I sit on the far right on the outer seat of the altos if I can. I have a rather low-grade claustrophobia, but I can manage it fairly well. I can sit in the middle... but it will take energy.
When it is night and time for bed, even in my own home I always feel relieved that I can go in my bedroom and shut the door; moreso if I am in company. Heck, I'm even relieved to shut the kitties out! They are distracting and wakeful. So you can imagine when I am at my yearly work convention with 12,000 attendees, and I'm running the General Information booth! So many times co-workers or friends want to go out and do something in the evenings... I just want to go home and recharge.
Conversely, once I've recharged, I need to expend some of that energy. I do need to be around people on an almost daily basis, but for much less time than everyone else, it seems. This is one reason I suspect I'm meant to stay single. I simply can't imagine what it would be like to have a husband who was always around!