If you show compassion toward someone who then takes advantage of that compassion, do you back off on being kind, helpful, and accommodating? Or do you try even harder by showing them even more compassion in hopes they will finally "see the light"? In order for compassion to work, it has to come from an even deeper place of compassion in you... not for others, but for yourself. Then, when you are abundant in self-compassion, you will be able to show genuine caring and compassion for others with no drain on you.