How do you rationalize gratitude?

Gratitude is about giving back for the good contributors in life, for adding meaning to it, thanking those who lightened the heavy loads..anyone that gives you all for your well being. I do not agree that it is purely based on biological cause.. not all women wants to give birth, some even kills them before they do or give them away...you yourself did not choose who to conceive you. Not all bio parents have the innate care..perhaps a filial respect must do because someone has given you life .. Before your existence, have you really knew that you have a life to live? Was it freely given to you or is it a coincidence or just a result of inconvenience to others? Living a life means you have to fight for it. Before a human is embodied with the flesh, the mind and the soul, we are to take care of it and thank those who have truly cared. I dread for one requires too much kindness and giving entitlement for every advances. Life is freely given, not a debt to pay. You have to live first to be able to live for others..just the same as you cannot give what you do not have.