I am obsessive about “thank you.” I was raised by a mom who said it to everyone who brought her food, rang her purchases, and worked at a customer service call center. It makes me believe that everyone is worthy of being thanked. (Ideally, thanked along with making eye contact.) Conversely, that it’s really diminishing when you’re not thanked at times that you feel you should be. Recently I’ve heard of that being an issue at work, or when you hold the door open for someone and they breeze on by*.
I’d like to think that people aren’t quick to thank in those scenarios because you’re just doing the job you’re getting paid to do, or because that guy could have opened the door himself and didn’t need you to do it for him. In those cases, I think it’s less about gratitude for the act in particular and more of a way of saying “I see you and I acknowledge the effort that went into this interaction.” And hey, everyone likes hearing that.

So, say thank you. No one feels worse when you do.

*My favorite thing to do when I hold the door for someone and they don’t acknowledge me is to say “You’re welcome your majesty” in a just-audible voice. Yep, I’m a winner.