"So you're a lefty?"
Years ago, I stopped making smart ass remarks to this inane question.
"No, but my right hand has a small patch of gangrene" and "No. I like to rotate my hands like we rotate our tires, so I don't wear them out unevenly" were fun things to say but never truly appreciated.
Instead, I simply answer the question now:
"Yes, I'm left handed."
Then I wait for what the person will say next, hoping that it will be, "I'm sorry. That was an incredibly stupid question."
It's never happened.