Giving of yourself to those who do not appreciate it or who take advantage of it is akin to stealing.
They are not stealing from you, but rather you are stealing from others.
By giving your most precious resources, your time and attention, to people who do not value what you are giving, you are robbing those who are genuinely need and will appreciate your help of the ability to receive it.
For this reason, you must learn to be discerning with what parts of yourself you give and to whom you give them.
There is deep joy and fulfillment in giving freely of yourself to those who need and want your help and you owe it to yourself and them to be available when the opportunity arises.