Nerd: "You know, for someone who has had two hours sleep, I feel surprisingly chipper to-day!"
Me: "Chipper?" Let it go. Walk away.
Nerd: "So, what do you do in your spare time?"
Me (not wishing to reveal this place): "Well, I do lots of walking..."
Nerd: "Oh, I'm quite partial to perambulating myself!"
By this point, I'd had just about enough and said: "Right, do you know what that word means?"
Nerd: "Yeah, it means walking..."
Me: "No, it means, 'I'm an arsehole.'"
To that, he had nothing to say.
Would you have said any different?