Deep brain stimulation is often described as a modern medical technology, but it is better understood as the current stage of a long scientific and clinical evolution. The ideas behind DBS emerged from early attempts to understand how specific brain regions influence movement, behavior, and perception. Over time, irreversible surgical approaches gave way to methods that emphasized reversibility, adjustability, and long-term safety. Advances in neuroscience reframed symptoms as products of dysfunctional brain circuits rather than isolated structures, which reshaped both surgical targeting and programming strategies. At the same time, progress in imaging, electronics, and data analysis transformed DBS from a blunt intervention into a precision therapy. Today, DBS continues to evolve toward personalization, signal-guided stimulation, and broader ethical awareness, while still operating within real biological and technical limits.