Medicine is already paying off

While in nyc to celebrate Swati's birthday, four of us piled into the back of a cab to get from the financial district to East midtown. Someone asked a question about research and I made some mildly medical comment in response. The cab driver then turns towards the backseat and says, "My hemoglobin is 9 and I have diabetes, should I be worried? What do I do?" I babbled something about glucose and blood transfusions (did he mean his hemoglobin level or his hemoglobin A1c?) followed by a strong wording of caution that I was only a student and that he should speak with his regular physician. His reply - "you are a very good doctor, I turn the meter off now."