I knew a guy who knew a guy who, back when the Soviet Union was a going concern, was solicited by a really attractive streetwalker in Moscow, and took her back to his room.

Later on, he asked the standard "What's a nice girl..." question. Turned out she was a fully licensed and practicing cardiologist, but couldn't live on what the state paid doctors, so she moonlighted.

That's the story I got, anyway. The guy might have made it up because he had a problem about socialized medicine, I suppose.

Peter