True story.
A friend of DH’s in grad school got married to lovely gentleman from Israel. Ari had his PhD and had trained both in Israel and Germany. As is the European custom, he always used his title when making reservations. He had booked a week at very nice B and B in Maine for their honeymoon as Dr and Mrs Z.
One morning while waiting for his wife to come downstairs, he was sitting on the porch of the house when an older woman also staying at the B and B comes up to him. She mentioned that she had overheard that he was a doctor when the couple was checking in. Dr. Z nodded. Yes, I am Dr. Z. The woman then proceeded to spend the next 10 minutes listing all her aches and pains and diagnoses. Dr. Z listens gravely, nodding occasionally at the woman and when she finally winds down, he looks at her quite seriously and says, “that’s all very interesting, but I am a Doctor of Mathematics.”