Snappy comebacks for "I'm a Doctor."

"Oh good, let me tell you about my gal bladder."
"Let me give you a hint, there is no need to point out the obvious."
"I know, I got a flyer in the mail that you were coming."
"So you are an expert in only one thing."
"I once got a gold star for drawing a monkey in second grade."
"Oh, is someone sick?"
"Proctologist?"
"Yes you are and that's why you were invited."
"Do you know Dr. Phil?"
"You must be really smart."
"Did they waive your entrance fees to get in here?"
"Can I use you as a reference?"
"Yeah, I saw your name on the restroom wall."
and...