We owe our brains to our primitive ancestors. In order to master a particular skill such as making tools or hunting, they had to practice, and practice enough until the skill became second nature. Once they had mastered basic skills that were necessary for survival, they could focus on higher level thinking.
"The great salvation for all of us is that we have inherited an instrument that is remarkably plastic," writes Robert Greene in his book Mastery. We have the ability to learn, adapt and master time. Developing mastery is not so different from our prehistoric ancestors. Those who excel happen to have the ability to practice harder and faster, as Greene argues, "all of this stemming from the intensity of their desire to learn and from the deep connection they feel to their field of study.