Going Home and Crashing

I got asked a question, I got asked a question! (Picture me doing a little dance and singing that. I'm a tenor second, long brown hair in a braid, brown eyes, glasses, roundish face, if you feel like being accurate in your picturing.)
No, really, I like answering honest questions.
Anyways, from Traci in the comments on Functioning Labels:

Honest question - what is it about coping with social situations that makes you go home and shut down. Is it an emotional reaction to feeling that you might make mistakes and be judged because of it, is it simply exhausting to have to try to function in such a challenging environment, is it a cultural message that if you cannot function adequately (I have no definition for adequate) in that kind of setting that discourages and defeats your ego. Several people in my family are introverts who react similarly whereas I am an extrovert and I probably don't really do the whole social cues thing that much better than they do but it doesn't leave me feeling distressed to the same degree. I am trying to understand and learn more about autism.

So.
Hi Traci!
Um.
I'm pretty sure all of those things are part of it to varying amounts, and I think that "interacting with people takes energy, regardless of environment or desire" needs to be part of it. I am introverted, I think. Not all autistic people are, but I think I am.
Point by point, each piece and how I think it is relevant.

• An emotional reaction to feeling that (I) might make mistakes and be judged because of it.
  Well, more knowing that I will. Because I will. Judgement varies, my friends tend not to care, some family members do, some don't. Strangers I usually have no cares to give as to what their judgement is because social interaction is tiring. Since this is a crowded gathering, I assume there is at least one person there whose opinion I care about. If not, I just wouldn't go, because these are exhausting. I think this one only comes into play with the kinds of gatherings where I am expected to fake neurotypical, since I'm actually pretty good at Autistic-style social interaction. Among other things, we count "parallel play" as totally being socialization. I'm not sure why you neurotypicals disagree. (Jokingly threatens behavioral therapy to make you get it. But I wouldn't actually do that because it's not ethical at all.)
• Simple exhaustion from trying to function in such a challenging environment.ALL THE YES. No, really. This is huge. At the noisy, crowded gathering that I mentioned, I can tell you 100% that I am experiencing sensory overload. After presenting at a conference recently (Debilitating Queerness, specifically,) there was a dinner at the home of an organizer that was open to presenters. I went. I had a good time, mostly, but that place was loud, and it was crowded, and everywhere was people, and I have trouble focusing in on one conversation and tuning out the others, and I was already tired. I... actually crashed at the party. Like, a complete crash, fell asleep there and everything, and it took my friend about 10 minutes to wake me up so I could leave. It was that exhausting. Other things I need to worry about at parties include finding food that I can eat and something that I can drink. Sensory issues can make that harder too, since I can't drink anything carbonated, scrambled eggs are a texture issue, and anything minty is a nightmare. (Oh, and did you know that people like to have minty breath at parties? AAUUUGGGHHH) Seriously, this is an environment that would exhaust me even without having to handle social interaction.
• My addition: Interacting with people takes energy, regardless of environment or desire.It takes less energy to interact in an Autistic fashion than to try to interact in a neurotypical fashion (I can use gchat, Facebook chat, Tumblr, and similar things with much less energy expended than I can for going to a party. Talking to one person face-to-face is somewhere in the middle, phones harder than face-to-face but not as hard as a party, generally. Though if it's an Autistic party, the party is going to be easier than the phone. But regardless of exactly how I am interacting, the energy needed is not zero. Use too much energy, and when I get to a place that it is safe to crash, I will. Use up too much beyond that point, and I may just crash wherever I am. 
• A cultural message that I can't function adequately in that kind of situation that discourages and defeats my ego.That message it out there, but I grew up with the people around me generally not knowing that I'm autistic, so I didn't get all that much of that message. I get it online more than anywhere else, and it tends to send me into angry tell everyone why they are wrong and exactly how they are hurting people mode. Which is a tiring mode to be in so I shut down afterwards, but it's not the message itself directly shitting me down. The message I got tended to be that I was able to do it and that everyone knew I was able to do it (only half-true. I can do it for a limited amount of time and then crash,) so I was just being bad when I crashed. Or people were just confused. It depended on who I was with. But the message I got was more that I was bad because I didn't care enough to do it than that I was broken because I couldn't. Neither is true, of course. I can for limited amounts of time, then I'm done, and that's OK. 

In order of smallest effect to greatest effect for the crowded, noisy gathering that I referenced in the functioning labels post, I think that it would be the cultural message, then the fear that I will be judged, then the fact that interaction is tiring, with the environment as the biggest thing. Dealing with my teachers, the cultural message is still smallest, but the environment is almost as small, and then interaction being tiring is a thing. The fear of messing up and being judged is the biggest one there, since teachers actually have the ability to mess things up for me and some have tried (not recently, but that's not the kind of thing you forget.) Hanging out with a few close friends, the interactions being tiring one is basically all that is in effect, which is why I last much longer with them than I do in basically any other social situation. It helps that they know I'm autistic and don't much care how autistic I act. When I told them I had finally gotten an official diagnosis, some of my good (high school) friends reacted with surprise... at the fact that I hadn't had one before. It wasn't a big deal to them because they liked me for the person I am, and I am autistic.