In this 2003 article from Risk Magazine, Emanuel Derman says it is essential for the aspiring super-quant to overlay theoretical knowledge with pragmatic common sense.

For the past few months, I've been teaching financial engineering at Columbia University, where I've been struck again by the difference between what can be taught in school and what can be learned on the job. Most of my quant generation arrived on Wall Street ignorant of financial theory; we began to learn its principles under the duress of having to quickly do something practical for someone on a desk. Nowadays, there's an entire industry devoted to quant training. But in many ways, quantisation still requires apprenticeship, and so, for a recent conference talk, I tried to think about some of the things you discover when you finally put your training into practice.