Excellent article on Times Magazine, titled "The science of experience".
There is an interesting experiment with two nurses, one with 2 years of experience and the other with 25. They tend to a robotic patient in a simulated environment, the junior nurse nearly kills the patient; the senior nurse moves across the run with far more confidence and speed, actually killing the patient in a shorter period of time.
A quote to motivate you reading the article:
Ericsson's (Dr. K. Anders Ericsson) primary finding is that rather than mere experience or even raw talent, it is dedicated, slogging, generally solitary exertion — repeatedly practicing the most difficult physical tasks for an athlete, repeatedly performing new and highly intricate computations for a mathematician — that leads to first-rate performance. And it should never get easier; if it does, you are coasting, not improving. Ericsson calls this exertion "deliberate practice," by which he means the kind of practice we hate, the kind that leads to failure and hair-pulling and fist-pounding.