[donnfelker]

Doctors "practice" medicine. Know one knows it in and out.

Remember that next time you get a diagnosis. "Doctors practice medicine."

[27182818284]

When doctors "practice" medicine they aren't saying "We're amateurs just like band practice." They're just using the traditional wording. You also here this with other older professions like law.

http://www.etymonline.com/index.php?term=practice