On the topic of question, what about the 'can I ask a quick question'? I have been known to reply, 'you just did'.
I'm very glad it's not just me who does this!
I use it from time-to-time in everyday use, but will use it nearly every time one of those people who've set up a booth in the middle of a popular shopping centre approach me with that question. It's so much more enjoyable right there in a public place!
The best one was a few years ago and went like this...
Them: 'Hello there, sir. Can I ask you a quick question?'
Me: 'You just did.'
Them: 'No, that wasn't it.'
Me: 'Well, you shouldn't have wasted it then, should you?!' [
Smile cheekily, and walk away]
She stopped walking after me, smiled defeated, and returned to her booth to pester the next sucker who made eye contact.