Do not spend time on people who aren't grateful. Those are the ones who take blessings for granted and live a life that lacks empathy. Your time once spent won't be gained back even by spending millions. So make sure you spend it wisely on those who respect your efforts and are grateful for the support they gained. As well, build this quality in your own life. Be grateful. Every interaction matters. Do not waste your energy and time on people who don't deserve it.