Neurology is a discipline of patterns: pulses of symptom clusters, rhythms of onset and progression, and the recurring motifs of history and examination that allow clinicians to separate the startlingly similar from the genuinely interchangeable. A good differential diagnosis in neurology is less a list than a map — one that shows likely pathways, dangerous cliffs to avoid, and routes to confirmation. “Neurological Differential Diagnosis” as associated with clinicians such as John Patten (whose name is commonly linked with practical guides and teaching materials in neurology) invites us to reflect on the mindset and methods that convert a bewildering set of complaints into focused, testable hypotheses.