In modern brain research, groundbreaking discoveries have been made. The so-called plasticity of the human brain means that it is changeable, expandable, and adaptable throughout life. Contrary to the previous belief of scientists, even the mass of brain cells is not definitively fixed but can increase over the course of life. According to the latest findings from brain researchers, the way we use our brains has a decisive impact on which neural connections are formed and stabilized or destabilized. The inner structure and organization of the brain thus adapt to its specific use. However, if a person's brain develops according to how it is used and has been used so far, the question arises of how we should actually interact with our brains to allow for the full realization of the potential within them. In an easily readable, vivid language, neurobiologist Gerald Hüther explores this complex of questions and arrives at insights that shake our current worldview and compel us to take on something we have too readily handed over to other authorities: responsibility.