Nephi marvels at his brothers' rebellion. Part of any good rebellion is to forget the goodness of God. Laman and Lemuel had seen an angel, been preserved by the hand of the Lord, and had known of the great blessings given to the children of Israel as God's covenant people. Still they chose to rebel. Thus we see how quick the children of men do forget the Lord their God (Alma 46:8). Many latter-day saints have fallen because they have likewise forgotten the goodness of God. How many have at one time had strong, irrefutable testimonies only to be dimmed by the amnesia of inactivity and iniquity? Maybe that is why the Lord has asked us to partake of the sacrament weekly, remembering the body and blood of Christ, that we might not forget the goodness of God.