Ok, here goes. A 1200-word post - that's what you get for asking me to explain my entire belief system ;)
(For reference purposes: the post I am expanding on is here.)
All of the responsibilities I listed (in the paragraph beginning "The word 'responsibility'") are things I try to do myself. Even the traits I list in the next paragraph aren't things I necessarily object to. What I object to is making those traits so paramount in the structure of morality that they become the reason that you're doing everything else. Rather than being nice to people because it strengthens community bonds and therefore your own position and quality of life, you're expected to be nice to people because it's the right thing to do. Rather than keeping your house clean because it makes your life easier to be able to find things, and more comfortable to be not living in a cloud of dust, you're expected to do so because it's the right thing to do.
What I object to are the blind, unyielding, arbitrary rules, the ones that say this is so because it is so, and damn you for even questioning it.
Another way to put this is to consider how a thing might be good if done for the right reason, but bad if done for the wrong reason. The reasoning behind any belief, moral, or behavior may not have that strong of an outward effect in the short run: someone who works hard because it's what they should do, and someone who works hard because they love their work and barely notice that they're "working", may seem equally well off at first. But I think that twenty or thirty years down the road, the first person is considerably more likely to be a depressed, alcoholic wreck, still doing well at his job but having lost everything he actually cared for. (No, it's not that simple, I know – but you get the idea.)
My role model for the responsible adult: my father.
Fortunately, he's much better now. But this is how he was when I was growing up. He was the personification of "repressed". He bottled up anything that might even possibly cause someone else to be uncomfortable or unhappy.
If my mother drove the car roughly, he would wince and groan, but flat-out refuse to say why. His parents drained us of money for years because it took him years to be able to tell them that his wife and daughter came first. The house had to be clean if anyone came over, because what would they think if they saw a house that looked lived-in? He worked himself to the bitter edge in his writing (he's a novelist) – and this is my theory, but – in part because he felt guilty for not having a "real job" with steady income, benefits, all that stuff. (My grandmother didn't help here by endlessly asking when he was going to get that "real job".) Around strangers he would be jocular and friendly, but empathically be screaming to be let out. And God forbid that any of us should bring up a topic even potentially flammable, or state a solid opinion; that might offend somebody!
Now the bad thing about this (besides the fact that it made him and us miserable) is that it did teach me that a good, polite person was one who never, never put their own needs above those of others. The good thing is it made me not want to be "good", because I saw how miserable it made him.
So everyone has personality traits that they aren't comfortable with – whether it be because they are trying to change them and failing, or they think society frowns on them, or whether they just can't rid themselves of that nagging feeling that it's not "right" (whatever "right" means). I have a theory that people gravitate towards religions that either let them justify these traits or more effectively counter them. From my father I both inherited and learned the tendency to self-denial and selflessness that would have fit in just great in evangelical Christianity. But because I saw how this fucked him up, and how the same tendency was fucking me up, I went the other way, to a religion that encourages you to put yourself first: Thelema.
Do what thou Wilt shall be the whole of the Law.
A lot of people tend to be horrified when they learn this, the primary tenet of Thelema. "Doesn't that mean do whatever you feel like, fuck everyone else?" they say.
No. It doesn't. Notice that "Wilt" is capitalized. This refers to your True Will. The overarching purpose of your life, that task for which you are ideally suited by virtue of being who you are, that Great Work which will enable you to fulfull your greatest potential. A Thelemite's life is devoted to finding out what their True Will is, and accomplishing it. Everything else is secondary. (Love is the Law, Love under Will.)
Every Man and every Woman is a Star.
Each and every person has their True Will to find and do. Not just some chosen few, not those who are "saved", not just Thelemites. Each and every person has their Will, and their supreme right to do everything in their power to accomplish it. And because people aren't perfect, and will make mistakes, this means that toes will be stepped on, punches will be thrown, and feelings will be hurt. To put it mildly. In the ideal – if everyone knew their Will perfectly and devoted themselves to it – the entire universe would just fall into place and run smoothly, no one infringing on anyone else. But the universe is not and never will be an ideal place (that would be too darn boring, for one thing). And if I think the next step in my True Will is going to hurt someone – I'm still going to do it. To do otherwise would be betraying everything that I believe in. But I will never hurt someone for the sake of hurting them. And I will certainly try not to hurt anyone for the sake of anything less than my Great Work.
I am fortunate enough to have gotten a pretty good idea of my True Will relatively early in life. And though I didn't do it in the most polite or painless of fashions, I have managed to get my life on the track where I can pursue it. While I'm sorry that the people I ran over on the way got hurt, at the time I didn't see any other way to do it, and so I regret none of it.
So yes, by some people's lights I do live selfishly. I keep friends around because they make my life interesting, and try to make them happy because it makes my environment a happier and healthier place. I pay my bills because otherwise the nice men in the blue coats would come and take me away. I eat, and sleep, and brush my teeth so that my body keeps functioning reasonably smoothly. I pursue new interests and activities, and enjoy life, to keep my mind awake and active. All so that I can more effectively accomplish the Great Work.
Love is the Law, Love under Will.