The final problem with the ten-thousand-hour rule is that…
The final problem with the ten-thousand-hour rule is that, although Gladwell himself didn't say this, many people have interpreted it as a promise that almost anyone can become an expert in a given field by putting in ten thousand hours of practice. But nothing in my study implied this.
— from Expanding Your Range (Growth/Change/Education/Learning/Habit) · Peak: Secrets from the New Science of Expertise by Ansers Ericsson and Robert Pool