To put things briefly, it looks like you've reversed most of the things I said.

I'm talking about "you" (as in, any given individual that finds themselves in a situation where they think they are too self-involved). I can't fix anything for you and I don't want to. I'm just saying, this seems to be one of the things that needs to be done. By me. By anyone who thinks they are too self-involved (and by anyone who doesn't think that but still IS too self-involved). Certainly if they are aware of a sense of excessive self-involvement and they want to change that, the only way to do so seems to be, well.. doing something that moves their locus of attention away from themselves :)

It's what I'll do because I want to be less self-involved, and if anyone else wants to be less self-involved, I believe that this is an effective course of action and hope that they try it. And yes, I believe that people being less self-involved (among many other necessary improvements) is essential to a better society. That's all.

Do you think maybe I'm the one who should be deciding whether this is a problem at all, and whether/how I should fix it?

Totally. That's what the entire thing is about! It is your own problem if you have it, and this is a way that you can address it! And others have it too ( I will absolutely maintain that excessive self-absorption is a problem every human being faces), so seeing you taking action to remedy it in yourself can also encourage them to change their actions.

Social norms are definitely written mostly by extraverts. The only way that's going to ever change is if somehow extraverts decide collectively to be less involved in socializing.. and introverts decide to be -more- involved in socializing. (I'm stating this as a logical necessity, because AFAICS the reason that social norms are written by extraverts is essentially self-selection.).

I recognize this and that's why I'm promoting taking responsibility for saying 'no, I don't want to talk right now' as well as promoting getting involved -- because as far as I can see, there is no alternative that preserves the possibility of people being able to develop relationships beyond merely what is expected in their environment. I'm not saying it's easy to say no, I'm saying it is your responsibility to do so at times, just as it's your responsibility to solve the problem of self-involvement if you have it. You seem to agree with this principle, seeing as you identify as an introvert and are speaking up :)

I've read and discussed temperaments in general, and introverts/extraverts in specific, a lot. I can recommend Dorothy Rowe's books on the subject (eg. 'The successful self'), as they seem to be the only ones that manage to strike precisely at the heart of things.

I am quite familiar with the fact that introverts have difficulty saying no, or to put it another way, being impolite. Also with the fact that they spend a lot of time inside their own head. If you want to see that I can appreciate their good points, I can say that they typically are better at methodical thinking and in general anything that's highly structured, they tend to have a stronger sense of self, and are better at deciding on and following principles. They tend to have fewer relationships but be more invested in the ones they do have. A majority of artists and writers are introverted. Naturally I don't have experience with what it is exactly like to be an introvert, but I do understand that for introverts, essentially the thing that scares them the most is losing control over themselves, so they spend a lot of time honing that control (largely by carefully maintaining and building on their internal meaning-structures). I recognize that being interrupted in this process can be quite jarring. I do maintain that if a person then experiences seething rage or other extreme emotions after being interrupted, that's a problem in their thinking they need to fix.

Fair?