In a lot of cultures, saying "thank you" and "you're welcome" are a part of day to day politeness. It can be easy to just rattle them off without really paying attention, but maybe they're more important than that. Saying "thank you" is a way to acknowledge the personhood of the individual in front of us, and the energy and effort they put into doing something for us. It reminds us that we are supported and nurtured, and that other people are a big part of the way that the Force expresses its care for us. Saying "thank you" reminds us to stay humble and be grateful for the work that other beings do for us, whether directly or indirectly. "Thank you" can even be a way to acknowledge the culmination of many lives and circumstances coming together to support us. In fact, "giving thanks" is another way to express the idea of saying a blessing or prayer before eating, and eating is a clear example of many people and processes coming together for our personal benefit, from the farmer to the soil and sun and rain to the market to the cook, and every miraculous step in between. 

Saying "you're welcome" in answer to a "thank you" can be more than just an automatic response, and deeper than just acknowledging our side in a single transaction. It is a way of accepting that we do put effort into supporting others, that we appreciate their acknowledgement and gratitude, and that we realize our role is important. We let the other person know that we are glad to be a part of their being nurtured and nourished; they are welcome to our support and we give it freely.

When we consider the deeper meanings, "thank you" and "you're welcome" can be another way to say "namaste," which means that the divine in me recognizes the divine in you. We are all interconnected, and taking time to consider and be genuine with social graces like "thank you" and "you're welcome" can turn them into little rituals to remind us of that.