Adult brains were still thought to be relatively unchangeable. From the late 20th century onward, studies showed that adult brains can reorganise in response to learning, changes in sensory input, or physical injury. The brain changes most reliably in response to repeated, focused and meaningful engagement that requires attention, effort and feedback. Repeatedly engaging in tasks that stretch your abilities leads to changes in both brain activity and brain structure, even in older adults. The issue is that meaningful brain change happens most when learning is challenging, varied, and connected to real life.