A woman interrupts their conversation to ask the doctor some sort of medical advice. The doctor tells her what he can then sends her on her way, then turns back to the lawyer.

“Man, I get so tired of people bugging me for medical advice,” the doctor says. “I never see people do the same with you for legal advice, how do you keep them away?”

The lawyer says, “Every time someone asks me for any advice, I just send them a bill. Keeps people away like a charm.”

“That’s super smart!” the doctor says. “I’m gonna do that!”

The next day, the doctor makes up his bills for all the people who asked him for medical advice, and he takes them out to his mailbox. He opens it up, and he finds a bill from the lawyer.