Stories of the righteous and gratitude

There are many stories about the gratitude of the great men of Israel (like Rabbi Shach, for example), and this is also presented as a central element in Judaism. After reading all the stories of the great men of Israel and their gratitude practices, I calculated that there are many people to whom I owe gratitude, and if I try to show gratitude to everyone in sufficient measure, I will have no time left for anything else. On the other hand, it is heard from the stories about the great men of Israel that they devoted a considerable amount of their lives to this and that it is truly a building block in the foundation of Judaism. I usually try to say thank you from the heart and remember that I owe gratitude, but not always (or often) do I "return the favor" – for example, traveling from Ma'alot to the central region for a wedding of someone to whom I owe great gratitude and who wants and cares about me coming – it is very difficult for me. What do you think?