this has to do with the plasticity of the brain. The brain is highly plastic in childhood development, becoming less so by adulthood once development is completed. Thereafter, the brain resists change. The neurons in the brain can only make permanent changes "when the conditions are right" because the brain's development is dependent upon the stimulation it receives. When the brain receives the powerful stimulus that experiences like bereavement, life-threatening illness, the trauma of war and other deeply painful experiences provide, a prolonged and difficult internal struggle, where the individual completely re-examines their self-concept and perceptions of reality, reshapes neurological structures. The literature refers to turning points, defining moments, crucible moments, and life-changing events. These are experiences that form a catalyst in an individual's life so that the individual is personally transformed, often emerging with a sense of learning, strength and growth, that empowers them to pursue different paths than they otherwise would have. Steve Gregg acknowledges that much human suffering produces no discernible good, and that the greater good does not fully address every case. "Nonetheless, the fact that sufferings are temporal, and are often justly punitive, corrective, sanctifying and ennobling stands as one of the important aspects of a biblical worldview that somewhat ameliorates the otherwise unanswerable problem of pain". A second critique argues that, were it true that God permitted evil in order to facilitate spiritual growth, it might be reasonable to expect that evil would disproportionately befall those in poor spiritual health such as the decadent wealthy, who often seem to enjoy lives of luxury insulated from evil, whereas many of the pious are poor and well acquainted with worldly evils. Using the example of Francis of Assisi, G. K. Chesterton argues that, contrary "to the modern mind", wealth is condemned in Christian theology for the very reason that wealth insulates from evil and suffering, and the spiritual growth such experiences can produce. Chesterton explains that Francis pursued poverty "as men have dug madly for gold" because its concomitent suffering is a path to piety. G. Stanley Kane asserts that human character can be developed directly in constructive and nurturing loving ways, and it is unclear why God would consider or allow evil and suffering to be necessary or the preferred way to spiritual growth. Hick asserts that suffering is necessary, not only for some specific virtues, but that "...one who has attained to goodness by