Gratitude is one of the most beautiful virtues of human heart and is most cunningly abused by the wicked, evil people in world. I grew up with a woman who used to do minuscule things for us, me and my younger sibling, like gifting a dress, buying a dosa (a south Indian dish) or taking to a trip (minimum expense) and in return of those small generosities she bought our gratitude and slavery. We could not say “no” to her when her hopes became expectations and finally demand.
Gratitude is good, but if it is for an evil person keep it in your heart, and try to just return it in one way or the other but don’t become his or her puppet. Your heart may call you ungrateful once in a while but as long as you don’t harm your benefactor it is okay, some people help others to get free slaves, slaves who will do anything for them and won’t ask anything in return, will always praise them!