A middle-aged woman—known as SM—blithely reaches for poisonous snakes, giggles in haunted houses, and once, upon escaping the clutches of a knife-wielding man, didn’t run but calmly walked away. All because a rare kind of brain damage precludes her from experiencing fear of any sort.
![Head of grass snake looking at the camera ( portrait of Natrix natrix).](https://hmhfyi.com/6-12/wp-content/uploads/sites/4/2023/08/fyi_g06c01-g08c02_lifewithoutfear.jpg)