In the Pachad Yitzchak [Chanukah Maamar 2], he notes that in lashon hakodesh the word הודאה means both to thank and to admit. What is the connection between the two?
People, by nature, don't like to feel that they need other people. We want to feel self-sufficient. When we THANK - we are ADMITTING that we need the other person and couldn't have managed the same on our own.
It is much easier not to thank because then we can continue living under the illusion that we are self-sufficient. When we bow our heads and say a sincere thank you we lower ourselves and elevate another human being.
The Rosh Yeshiva writes in the Pachad בטבע הפרא של כל אדם גנוזה היא ההנחה של כוחי ועוצם ידי עשה לי את החיל הזה
In the animalistic nature of every man reposes the quality of "my strength and the power of my hands accomplished for me this success".
The more we can thank - the less of a פרא אדם we become and the more humble we become.
What better quality is there than humility?!:-)
לזכות אהובי ר' הירש יונתן בן ר' מרדכי אפרים לברכה והצלחה!