So the other day, a friend of mine walked up to me, scrunched his nose and said, "Ew, what is that smell?" But I didn't smell anything. So I panicked. What I should have done is say, "Yeah, what is that?" That way my friend would think nothing of it, and I could have moved on with my day.
Instead, I sniffed deeply twice and said, "Hmm, I don't smell anything." My friend then became suspicious of my motives. I could see it in his face (Is he pretending not to smell it?). Then I'm pretty sure he became suspicious of my guilt (Is he the source of this foul odor?).
Then he said, "Really?" and I said, "Yeah, really. I don't smell anything." So then he lost his trust in me. (His inner monologue - "Okay, he either farted and doesn't want to admit it, or he's trying to make me think I'm imagining smells. Either way... not cool.") Then he left. And I'm certain that he immediately went and told all our our mutual friends ("Can you believe he did that? I mean, it was so obvious."). He probably insulted me ("He's such a flatulent liar."). Word then spread via Facebook, MySpace, YouTube, and Twitter (even my mom unfriended me). Then my life collapsed in on itself like a dying star ("No one loves me!")
So now my policy is to always admit to smelling something. Even if I can't smell it. Even if I think it smells like strawberries. And even if I had the new cabbage-chili-salsa burrito from Taco Bell and I am the source.