Who hasn’t wanted to look inside someone’s head, especially when that person is acting strangely? A look into the brain can indeed be revealing, both from a medical and neuropsychological point of view, but also from an educational one. This is literally the case with ’P-0255’. But P-0255 is not an old personnel number as a colleague suspected, nor is it a neuroimaging scan; it is the number of a specimen from the University Museum’s pathological brain collection that shows a particular form of traumatic brain injury: a coup contre-coup.