The Ramban (Shemos 17:16) beautifully highlights the importance of hoda'a, properly giving thanks: "V'ein Kel Elyon chafetz b'tachtonim milvad she'yeida ha'adam v'yode l'Elokav she'b'rao - Hashem has no demand of man, except that he should know to be thankful to G-d for having created him."
Rav Yitzchok Hutner explains that the term hoda'a has a dual meaning. In addition to thanksgiving, hoda'a is an act of admission: "Hoda'as ba'al din k'meah eidim dami - a litigant's admission is equivalent to the testimony of one hundred witnesses." Only when one who acknowledges that he is not self sufficient, but inherently dependent, can he begin to appreciate the goodness of others.
We often measure our thankfulness from the perspective of the one who performs an act of chessed - we ask ourselves, will he appreciate my gesture of thanks? To what extent did he go out of his way to help me?
Parshas Vaera provides profound insight into proper thankfulness and appreciation. The Medrash Rabba explains that Moshe Rabbeinu, who was saved by water and protected by the dust of the land, was unable to perform the initial makos himself. Yet how do we understand this sense of hakoras hatov? Surely the water and dust of the land did not go out of their way to aid Moshe Rabbeinu. Inanimate objects do not need and cannot appreciate our gratitude.
The inability of Moshe Rabbeinu to participate in these makos teaches us that hoda'a and hakoras hatov must also be viewed from the perspective of the beneficiary; the mere fact that Moshe Rabbeinu benefited from these inanimate objects elicited an abundant sense of hoda'a.
Accordingly, the gemara (Berachos 58a) contrasts the oreach tov, the appreciative guest, with the oreach ra, the ungrateful guest. Whereas the oreach ra minimizes his needs to express gratitude, claiming, "kol torach she'tarach ba'al habayis ze lo torach ela bishvil ishto u'banav - all the effort of the host was surely for his wife and children", the appreciative guest feels, "lo tarach ela bishvili - all the efforts of the host were exclusively for me."
The Vilna Gaon observes that each of us is a guest in the world. One could selfishly feel that Hashem creates little exclusively for me. True hakoras hatov and hoda'a, however, demand that as an oreach tov we view all chasdei Hashem as though bishvili nivra ha'olam - the world was created for me.