The trying to conquer the Cinnamon Challenge isn't exactly my idea of a good time, but people still try all the time. After Shoenice ate an entire bottle of cinnamon, the magic was kind of ruined for me. Anyway, the guys from SciShow laid out why the human body reacts so adversely to shoving a tablespoon full of cinnamon down the throat. 

[H/T: Devour]