The ability to spend 10,000 hours of deliberate practice on something is an inherited talent.
I really mean that. If you have evidence for that belief, please share it here. The leading world expert on the subject of development of expertise, K. Anders Ericsson,
http://www.psy.fsu.edu/faculty/ericsson.dp.html
is decidedly not of that opinion, after having seen many examples of introducing systematic deliberate practice into the environments of people who formerly didn't have opportunities for such practice.
Maybe nobody introduced "systematic deliberate practice" to them? Or, you know, maybe some people are just lazier than others.
Good question. Have you examined any research on the issue? What sources do you recommend?
Being able to spend that much time in that focused of an effort seems like a talent or perhaps a "condition" like Asperger's.