So, what does happen to your brain at 25? And how did so many people get the idea that something profound happens at that specific age? The past two decades of neuroscience research provide some clues. A huge breakthrough in how we study brains and a few intriguing kernels from studies seem to have become the basis for a powerful idea that reaches far beyond the facts. The real answer to these questions may lie in a culture that’s uneasily grappling with what science can (and can’t) tell us about ourselves.
Source: Brain development: The myth the brain “matures” when you’re 25.