They remain voracious - and will probably never consider themselves experts - because they are passionate about what they are doing. They are passionate enough

They remain voracious - and will probably never consider themselves experts - because they are passionate about what they are doing. They are passionate enough to not just 'practice' but to also know who the experts in their field are, know what those experts accomplished, and know what they themselves don't know. This 10,000 hours thing is an effect of expertise, not a cause. Focused passion * (time+talent) = expertise