Since this is apparently a music based study, I have a few ramblings...
In Music, you can spend the first half of your career identifying what is "good" sound, then you spend the rest of your life seeking consistency. Many will never be any better at identifying good from bad after 10kh than they were the first 20m.
I used to put in at least 35h a week at music, which makes 10kh about 28 weeks. Show me a musician who mastered an instrument in 7 months, let alone making music.
Its how they become the best they can be. But its no guarantee they will be the best compared to others.We tell kids that don't have much talent that they can still be successful if they work really, really, really hard.
Sometimes we even mean it. Maybe.
-W
35 hours a week for ~285 weeks is 10,000 hours not 28 weeks.