See also Bloom's two-sigma problem: <a href="https://en.wikipedia.org/wiki/Bloom%27s_2_sigma_problem" rel="nofollow">https://en.wikipedia.org/wiki/Bloom%27s_2_sigma_problem</a>
TL;DR:<p>Experts are always made, not born.<p>1. Practice deliberately — considerable, specific, and sustained efforts to do something you can’t do well.<p>2. Take the time you need — ability to attain expert performance is clearly constrained if you have fewer opportunities to engage in deliberate practice, since winning requires a training history comparable with that of other elite performers, nearly all of whom started very early.<p>3. Find coaches and mentors — development of expertise requires coaches who are capable of giving constructive, even painful, feedback, to extremely motivated students who seek out such feedback.<p>Real expertise must pass three tests:<p>1. Leads to performance that is consistently superior to that of the expert’s peers.<p>2. Produces concrete results.<p>3. Can be replicated and measured in the lab.