We set the course at the beginning of life, with consequences that accompany us and that we can influence positively or negatively through our behavior. Evolution has shown us how it works. Movement in a diverse and stimulating environment with a varied diet in a group is the basis for this. This activity stimulates the hippocampus, promotes neurogenesis, and stabilizes physical and mental health. This is especially true for the cognitive aging process, which is strongly associated with the hippocampus. The aging of the brain is the reversal of the process that increases its volume and cognitive performance. Alzheimer’s disease begins with typical changes in the hippocampus and, consequently, in the other brain areas connected to it. As the gateway for new experiences, the hippocampus must be stimulated and nourished to fulfill its function and remain “young.” In old age, it is not so much the quantity (energy), after all, we no longer go hunting daily, but the quality. The amount of micronutrients we need has not changed. Nevertheless, regular exercise is also essential, as it helps avoid stress. We can create a stimulating environment that challenges our ancestors. Appropriate measures are available. All of this helps to support the formation of the hormone brain-derived neurotropic factor (BDNF), which stimulates neurogenesis in the hippocampus and thus counteracts the dementia process. Last, social contact is essential to keeping the hippocampus and the rest of the brain active and preventing it from aging too quickly. The value of friends in old age is undisputed. Interacting with people close to me aligns with the social hypothesis of brain growth. What has contributed to growth can also inhibit age-related decline. Cognitive stimulation therapy starts right there and is thriving. We can influence some other risk factors ourselves. Good hearing is at the top of the list; if that is no longer possible, wear a hearing aid. Limiting alcohol consumption and not smoking. Experts have concluded that the measures described can reduce the risk of Alzheimer’s disease by almost half.