How do I get to Carnegie Hall?

Gladwell popularized Ericsson’s violin research with his catchy formulation, “the 10,000-hour rule,” which Ericsson paraphrases as the rule that “it takes ten thousand hours of practice to become a master in most fields.” This notion was “irresistibly appealing,” Ericsson notes, because it’s easy to remember and satisfies a human desire for simple cause-and-effect relationships...

Certainly, “the number varies from field to field,” Ericsson observes.