This book on presidential age is not about Alzheimer's Disease and associated pathologies of the aging brain. It is instead about the normally aging brain. Brains don’t simply develop and maintain their functionality into older adulthood unless otherwise impaired by neurocognitive disease. Were this the case, this book might be about leveraging prodromal biomarkers of neurodegenerative diseases to screen prospective presidential candidates. Instead, the normal decline age brings to all human brains begs a different type of book—and a broader and more blanketed warning about electing increasingly older presidents.