In my personal view, this rule is a quantitative version ofthe old saying: practice makes perfect, while many people hold a skeptical?attitude towards the time -10,000 hours. I will not address too much on how researchers get this number, instead,I am interested in how people spend this amount of time if they follow the rule. In learning process, there is a term called: cozy zone, which means you will not suffer when you practice something that you have already mastered. Onthe contrary, if you are trying to learn something new, you suffer more. ?So I think the 10,000h should be spent more?effectively, that is, adding the degree of difficult as practice goes.