I think welcome is a wonderful word. Someone told me in another state recently that I was "always welcome" to stay overnight at their family's home. It made me feel warm and glad to know that someone cares enough about me to always "welcome" me. It shows courtesy to others. Thank you is another wonderful couple words. Have you ever done a whole lot of work for someone and put yourself out for them but never been thanked for it. See how that feels and see why it really is such an important couple of words. :) And no, your question wasn't stupid. There are some on this site that really are, but this is not one of them.