C. O. Undercover

The Cheerful Oncologist visits his own doctor for a check-up. He doesn't tell the office staff that he, too, is a doctor:

As I introduced myself to the receptionist she asked for my insurance card and said, "Mr. Hildreth, please take a seat. We'll call you when we're ready." ...Did I hear correctly? She called me mister - Mr. Hildreth. Why, I'm a layperson again!
After a week of seeing patients and answering millions of questions I relished the thought of going through this visit anonymously. I smiled slyly and wondered how long I could go without anyone knowing my true occupation; after all, we medicos have big egos. Maybe I wouldn't be able to carry out the charade. I decided to give it a try - to fake being a normal person and see if the employees treated me differently than if I had brought a bullhorn and announced "WATCH OUT - I AM A DOCTOR!"

His discoveries are not to be missed. Example: "Patients who read of a new medicine have a better chance of getting helpful advice from the doctor if they bring the information with them, rather than say 'You know, doc, it's that thing they gave to all the baboons in China.' This doesn't narrow it down much."