The author has compiled knowledge about this natural remedy based on scientific findings and 87 years of life experience. He calls it "Juvenilization," which means maintaining the virtues of youth throughout one's life, both mentally and physically; thinking, feeling, and acting in a way that keeps one perpetually youthful. Key prerequisites for this are optimism, willpower, love, activity, and healthy sleep. During sleep, a person can rejuvenate daily. A criterion for juvenilization is the ability to care for oneself into old age. Juvenilization has nothing to do with anti-aging, which represents an unphysiological principle against aging and is referred to by the author as one of the worst buzzwords of our time. The author explains the process of healthy and unhealthy aging.