“Take care of yourself” was no longer a motto for the uber-selfish. It was actually a smart and sustainable way to live in the world. “Be nice” wasn’t about manipulating someone else into being nice, I could choose to be nice because I liked myself when I was nice.
Doing unto others slowly emerged as something that I could choose to do because it was a basic guideline for decent behavior.
One of the problems I have with therapists is that they tend to see everything in terms of "taking care of yourself." This might be necessary for the patient at first, but I think we need to go beyond that.
I think we should follow the Golden Rule not only because we choose to do it, but because it's the right thing to do, whether we choose (feel like doing) it or not. Sometimes I feel like "choosing" the easy way out, but then I catch myself and try to do the "right" thing.
There are various ways of "self-affirmation." Not all of them are right or good. In other words, I think self-affirmation needs to have a moral component (and no, I'm not a religious person).