Responsibility

Mitch,
I remember first long conversation about my beliefs of moral relativism, and you asked me what responsibility was. I did not have an answer. After discussing in detail why I have personally come to the conclusion that there is no universal moral truth, or rightness, you plainly asked me why people feel responsible, and I had no idea.
I was thinking about it today, and in a flash of insight, I came to the realization that perhaps feelings of responsibility are an inertia for wanting to maintain the status-quo. When one feels responsible for an event or person, they do so because they understand that their actions can affect that entity, oftentimes in a negative way. Because they may personally not want it to change, they in turn feel that they must calculate their actions to prevent "harm." Therefore, feelings of responsibility are simply an artifact of a culture's moral inventions, which has great control over individuals' decisions, as well has how they view themselves.
This, like the rest of my understanding of morality replaces the influence of some pre-ordained, universal, "God-given" truth, with the individual, who is essentially creating it on their own. Or, more appropriately, a society of people creates and controls this morality, while individuals who are a product of that society are enslaved by it (incidentally, perhaps to the same degree that they might be enslaved by a God who decreed responsibility and morality, because in both cases such standards are outside the control of the individual).
What do you think?

I think I should probably write up my original opinions on what morality is, for context, but I'm too afraid to, as I don't think I'm up to the task - speaking about something in a conversation is much more free-wheeling than trying to intelligently put it into words, for the scrutiny of others.