I think that expertise is the connection between knowing and doing.

"Some degree of derivative learning is necessary - BUT - much learning does not teach understanding. Only through experience and extensive practice and application will understanding and expertise arise."

-Heraclitus, 475 BC

New trader to Master Trader:

 "Sir, what is the secret of your success"? "Two words."

"And, sir, what are they?" "Right decisions."

"And how do you make the right decisions." "One word."

"And, sir, what is that one word?" "Experience."

"And, sir, how do you get experience?" "Two words."

"And, sir, what are those two words?" "Wrong decisions."