Here are a few quotes that I find relevant. 

 

1.  Letter to a young scientist

"You only see what you know to look for, and scientific training will give you much better eyes. Not because of the facts you learn they age quickly and you should always distrust them a little".

Gottfried Schatz, FEBS Letters 558, 1-2., Jan. 2004

 

2.  A famous American biochemist said this to a Harvard graduating class:

 "Half of what we taught you is probably wrong, but unfortunately we do not know which half".

 

3. and finally,

"To a science student, cramming facts is what practicing scales is to a piano student: there is no way around it, but it's not enough".

 

In summary: 

Medical science is a demanding field.  We must constantly refresh our comprehension of "facts" to hold us up to date.  Older "truths" become inaccurate and knowledge expands rapidly.  One must follow advances in the medical and related literature to remain competent.  Two sources that I find to be of great help are http://www.medscape.com and http://www.pubmedcentral.nih.gov/

Good luck!