NEW YORK (TheStreet) -- Benjamin Franklin - author, entrepreneur, scientist and revolutionary...Emilie du Chatelet - physicist, mathematician, mother of four, and early developer of financial derivatives...Thomas Edison - inventor, free-thinker, businessman and moralist... Throughout history, talented men and women have often been polymaths who spent their lives mastering many different skills and pursuing many different careers. After all, being a jack-of-all-trades is wired into our DNA; we're all descended from ancestors who survived and thrived by becoming adept in numerous areas of expertise. Sadly, such "mile-wide" ability is in far less demand today. Instead, welcome to the world of "mile-deep" vocations -- Renaissance Men and Women need not apply. A generation ago, bank training programs eagerly hired art history, Russian literature and semiotics majors. My first VP title was the short and simple "Corporate Lender." Today, university sophomores and juniors are aggressively quizzed on financial minutia when applying for ten-week summer internships. And current VP positions have hyper-specific titles like " Americas Equity Linear Quantitative Research Algorithmic Trading Quant Development." Institutional narrowing and deepening is also a top-down phenomenon. Financial titan J.P. Morgan lived in five countries before the age of 21, spoke fluent German and French, collected priceless art, and built museums as well as billion-dollar conglomerates. Jamie Dimon, current heir to the Morgan Empire, has never lived abroad, speaks expletive-laden English, and lists "running" as his only hobby. The situation is no different at Goldman Sachs where CEO Lloyd Blankfein was well into his 40s before he learned that short-shorts and knee-high tube socks were less than conventional golfing attire; his predecessor Bob Rubin was almost 60 when he first heard of music icons Aretha Franklin and Eartha Kitt. So like it or not -- and to the almost certain detriment of the industry -- admittance to today's financial service executive suites requires that we first stifle our natural inclination to diversify our skills and explore different careers. Instead, we must put all of our eggs into the banking basket -- and watch it very carefully.