John Medina opens by contrasting the brain's actual evolutionary history — built for movement, novelty, and survival-relevant problem solving — with the sedentary, static environments of modern schools and workplaces.

The mismatch he identifies:

• The brain evolved in an environment requiring constant physical movement and environmental awareness
• Modern institutions demand sustained stillness and attention to abstract, often unchanging material
• This mismatch explains much of the attention and engagement difficulty common in traditional classroom and office settings

This framing sets up the book's subsequent chapters, each translating a specific piece of brain research into concrete recommendations for working around this fundamental mismatch.