I don't know about you, but when I look back on my growing-up years... you know, those formative years when you were gloriously ignorant of sex, fashion, computers and everything political... well, I remember the last words that followed me up the stairs every night like an echo..."and don't forget to brush!" I guess there were other important parenting directives like "sleep well", but that one, daily reminder, made a life-long impression on me.
And that gets me to the power of repeating words and ideas over and over, until they take root and can stand on their own as another person's belief system.
Now, the way I see it that can be a good thing, or a terrible thing. Good, as in the case of learning that brushing your teeth before bed every night is a healthy and good thing to do. Bad, as in repeating some lie over and over, won't make it less of a lie, it will just make it so familiar that it becomes reasonably believable.
We all know examples of the power of words. Pick and choose your carefully is another idea that I wish more folks would follow. That's why being a writer is so empowering to me and I suspect other writers; we get to find just the right words to make an impression on our readers; an impression that will be remembered, maybe even while brushing your teeth!