It becomes quite "forced" i feel. When it is like, not real, and when people start to doubt how much others mean to them. "Sorry" and "Thank you" become so commonly used, that they lose their meaning. Everywhere there is a sorry or a thank you, but how much of that comes from the heart? And what if it is only out of politeness that they are said? Doesn't that shows a lot? And yes, when you think you don't feel like saying a thank you because there's no need to, well of course it is only because of who you are. I don't think people should judge others based on themselves. Others do not say sorry or thank you because... well... they think that deep down, whatever that is done doesn't warrant a sorry or a thank you. Or they are just plain rude.