Only on the "CBS This Morning" podcast, geriatric physician Dr. Louise Aronson joins co-host Gayle King to share some of the common myths about getting older. In her book "Elderhood: Redefining Aging, Transforming Medicine, Reimagining Life," Aronson writes that peak happiness and life satisfaction is usually reached around age 60 or 70. She says we should think of old age as a "third act" of life, with unique ambitions and pleasures as we change throughout our lives.