Minding Ps and Qs, having good manners and generally trying to avoid the impression of being "born on a bus" are what good parents try to teach their children. Society as well puts a heavy emphasis on civility. In fact, browsing through many self-help and get-ahead websites, I noticed that gentility weighs prominently as a factor towards approval ratings and promotion.
However, the motivation behind being taught these values at home versus the workplace couldn't be more striking. When a parent reminds us to say "thank you", it is to ingrain within us qualities of gratitude and appreciation so that we will better develop as people. In contrast, a "you're welcome" suggested by an entrepreneurial magazine is a tip towards office advancement; whether or not we become a mensch as a consequence is not really part of the consideration.
This week's sidrah introduces the mitzvah of offering a thanksgiving sacrifice. The practice of thanking God for assistance in challenging circumstances is still with us today, with the recitation of the blessing of thanks, birchat hagomel, or preparing a festive meal of appreciation, seudat hoda'ah.
God doesn't need our thanks and instructions to show Him gratitude are not part of any clever self-promotion strategy. The goodness we receive from Him is offered, as a mother or father would, unconditionally with no strings attached. But just as parents guide children towards refining their character, so too can we find in our Torah opportunities for growth and self-development.