Fact: If you know someone (including yourself) farted, and you smell that fart, immediately you will react as if you got a whiff of the Devil himself. Then you'd hold your breath and fan your hands in front of you until you thought it was safe.

Question: Have you ever smelt a fart (most likely your own) where you thought, "hmm... if I didn't know this was a fart, I would mistaken it for the smell of food."? I know I have.