>>One of the fist things they tell you in medical school is that by the time you graduate everything you've learned will be obsolete. Some doctors stay up on things and learn new stuff -- some do not. That is one primary thing I look for in a doctor.

Certainly they told us that "practice" is well-named, since a medical career involves constant practicing of current and new treatments. With medicine one of the main drivers of scientific progress except in times of war, many jurisdictions now maintain CME (Continuing Medical Education) programs to retain license. One of the most difficult specialties outside the US would be General Practice since GPs need to practice in every area and stay abreast of an awful lot of stuff.