"We can glut ourselves with how-to-raise children information . . . strive to become more mature and aware but none of this will spare us from the . . . inevitability that some of the time we are going to fail our children. Because there is a big gap between knowing and doing. Because mature, aware people are imperfect too. Or because some current event in our life may so absorb or depress us that when our children need us we cannot come through."