A Word or Phrase

I was asked recently what phrase or word, other than "I love you", would I consider to be of paramount importance. For me it is "Thank You". Those two words can lighten my day. They can bring such a feeling of worth and can at times validate me.This means that when I receive a "thank you", I now know it is genuinely meant and thus making it so much more important than ever before. Today when I held the door of a shop open to allow someone to exit that person said "Thank You" and it certainly made my day as there is generally no acknowledgement.In fact fairly recently I held the door, open as I would, to allow a young lady to exit  rather than barging my way into a shop only to be greeted with "It is no wonder that women are still looked down upon, when we still have women like you holding doors open." I was so stunned that what to me was politeness would be seen as putting down women.I hadn't realised that things had changed so much that a gesture of thoughtfulness would be seen as an insult.  Things have changed. I hadn't realised just how much value I put on those two words. Does it matter then when people do not express their thanks? For me it is important but for others it is way down their list of priorities.  I have come to realise that I have to accept that difference, but with the proviso that the phrase "Thank You" is important to me and perhaps others need to respect that. Or am I asking too much?