If someone gives you the advice to stay calm, there are situations where that's totally manageable because you're overreacting. You just dropped an ice cream cone. There's a bee nearby. Someone argued that The Phantom Menace is better than Return of the Jedi.
Then there are situations where it's advisable you take that advice even if it seems impossible. For instance, if you're told to stay calm after a cheetah jumps into your car. A recent safari through Gol Kopjes, which has the highest concentration of cheetahs in Africa, saw that exact situation captured on camera.