Sometimes "thank you" breaks my heart

I love a polite child.I feel that if a child is rude it's because the parents haven't taught their child the correct behavior and in my mind there is no excuse for that. Oh,I know kids slip up now and then and that is perfectly normal but you know what I mean. That being said,there are times when I feel Lillianna is too polite.

Yesterday,Lillianna wanted home-made soup for lunch. She is keeping a food diary because we suspect she might be lactose intolerant and we are trying to see if there is a pattern. She handed me a bag of noodles and asked if I could make some soup. It wasn't my wonderful soup where the broth is actually made from a chicken. It was canned broth with some carrots thrown in for texture and then some noodles were added. I set the bowl on the table and Lillianna said,"Thanks for making me lunch,Mom.I love you."
Maybe I am too sensitive but that always makes me cry.I am happy she is polite but to thank me for just feeding her breaks my heart. As if I wouldn't feed her?

This past weekend Lillianna had a swimming pool birthday party at the local Y.M.C.A (no singing,please!)There was pizza and cake first then swimming. Before the pizza was even served,Lillianna ran over to me and whispered,"I have to go to the bathroom." Unfortunately the one and only bathroom that was open was way on the other side of the building. We walked as fast as we could.Lillianna hugged me and said,"Thank you for taking me to the bathroom,Mom." I laughed and said,"You're welcome but you don't have to thank me. I am your mother and it's my pleasure to take you to the bathroom." She had to make 2 more trips before she even ate her pizza.Each one was followed by a thank you and an apology. "I'm so sorry I have to keep going to the bathroom,Mom." This kills me because I have never ever been mad that she has had to go to the bathroom in her entire life! I am always there for her in every way and I wonder why she feels the need to apologize for something like this.

Do your children thank you for everything you do? Do they apologize for things but you don't know why?