I've gotten better about saying no as I've gotten older. Well, partially... when I was a kid and teenager, I had no problems saying no and establishing parameters. Somehow, in my 20s-30s I caved in - was not myself, and in two different marriages. Today, I do what makes me happy and if something does not work for me, I state so and move on. No more guilt trips. When I say no to someone I say yes to myself.