Failure to Offer Gratitude

This was in my email yesterday, from a ministry called SoundBytes:

Several years ago I offered the invocation for commencement exercises at a large state university.  I remember one unprogrammed event above everything else.  At a strategic point, the president of the university invited the graduating students to applaud their parents and spouses, in appreciation for helping them reach this wonderful day.  It was a moving moment.

The president might also have invited the students to applaud their professors and librarians, the authors of their textbooks and of journal articles, the people who preceded them in research, and the citizens whose taxes had paid most of the cost of their education.  It would be a long list -- and a gloomy one for any egotist who might have thought he or she was self-made.  Above all, the president could have invited the students to bow in gratitude to God, the Source of life, breath, health, and talent -- including the vast mines of talent that most of us never begin adequately to explore.

-- J. Ellsworth Kalas in If Experience Is Such a Good Teacher Why Do I Keep Repeating the Course?  

Yesterday my post was about celebrating joy.  Thanksgiving is one of the ways that we can celebrate the joy in our lives.  Can our failure to do that sometimes be related to what Kalas says in this quote?  Could it be that we are egoists who think we are self-made?  Are we afraid to offer thanksgiving because it is an admission of our dependence on other people?  Our dependence on God?

What in your life do you fail to offer gratitude for because you think it is your own accomplishment?