Jacob Viner is one of the greatest thinkers in the Chicago school economics. He once talked about the relationship between interests and training in pursuing a professional career, and it went like this,
"...men are not narrow in their intellectual interests by nature; it takes special and rigorous training to accomplish that end.."
-- Jacob Viner, "A Modest Proposal for Some Stress on Scholarship in Graduate Training" (PDF)
By the way, as you may already know, Viner had a reputation as being one of the toughest professors at Chicago, and Milton Friedman was a student of Viner.