This chapter explores the incidence of giftedness, the parallels between degrees of delay and advancement, giftedness as an organizing principle, different levels of giftedness, typical characteristics throughout the lifespan, and why it is important to recognize advanced development as early as possible. Educators forgot the integral role of psychologists in the development of the gifted, and psychology abandoned the gifted. The 21st century holds promise of reconnecting gifted education with its psychological roots. Giftedness is a psychological reality—the opposite end of the spectrum from Intellectual Developmental Disorder, as it is referred to in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). When a psychologist evaluates a child and concludes that the child is gifted, it often has a ripple effect on the parents’ self-perceptions. Gifted adults, perhaps more than any other group, have the potential to achieve a high degree of self-actualization.