On a Friday night once a doctor and a lawyer were at a party, having a casual conversation. Folks kept walking up to them and interrupting, asking the doctor questions about their various ailments real and imagined, to which the doctor would graciously respond. After some time, the doctor asked the lawyer "I've been noticing that of all the interruptions we've had, no one is asking you for legal advice, but everyone's asking me for medical advice. Why is that, do you suppose?" The lawyer smiled and said "They used to ask me, too, and I found it very annoying. Now, if anyone asks me for legal advice at a party, I stop and give them my very best advice. And then in the morning I send 'em a bill for my services at my 'after hours' rate, double my normal rate! The word's out, and now I can have social evenings without annoying interruptions."
The doctor mulled this over, and in a few days decided the lawyer's solution to the problem was a good one, and so sat down and made out bills to all those folks who'd interrupted them at the party. He then walked out to his mailbox to send the bills off, where he found a bill from the lawyer.
Rick