Ten thousand hours is equivalent to roughly three hours a day, or 20 hours a week, of practice over 10 years... No one has yet found a case in which true world-class expertise was accomplished in less time. It seems that it takes the brain this long to assimilate all that it needs to know to achieve true mastery.
This Is Your Brain On Music: Understanding a Human Obsession (ed. Atlantic Books Ltd, 2011) - ISBN: 9780857895141