Paro is under pressure: What should he do with the Jews? They are overpopulating us! Can we control them? What will happen in a time of war? It becomes clear to him that as the leader of Mitzrayim he is obligated—for the security of his nation—to enslave the Jews to ensure that they do not rebel.
Chazal seem to look down on him for this action. Why is that so? Wasn’t he fulfilling his obligations as leader of Mitzrayim? Rav Yaakov Kaminetzsky (Emes L’Yaakov) answers that Paro’s fault lies in his lack of hakaras hatov.
My understanding of Reb Yaakov’s idea is that Paro does not really understand that all that Mitzrayim has was brought about through Yosef and the Jews. He therefore cannot lose his position to them because his position was brought about through them. In a sense, it is really their position! This understanding of hakaras hatov is that hakaras hatov is not like paying a debt to the bank: Once paid it is forgotten. Rather hakaras hatov means that the recognition of the good must remain in your mind forever.
I would like to add to this that Yosef was very loyal to Paro: He did not do anything without specific permission from the ruler. He did not even let his family come down without asking Paro first. At a time that the world was in a craze for food, Yosef had it within his bounds to make a coup, and yet he did not do so. Was Paro makir this tov? The “tov” being that the Jews are loyal—the Jews do not and will not revolt.
We must conclude that the idea of hakaras hatov is not just to acknowledge a single good act that was done in the past, but to recognize and identify with the act, the environment in which the act took place, and all the ramifications of this one act: To be makir all of the tov.