[imtringued]

Nobody who wants to learn a skill wants to master it in 20 hours. The entire point of this article is that the 10000 hours number is a red herring.

Spending every single day learning something is the exact opposite of a shortcut, it requires a huge amount of discipline. 20 hours spread over 30 days should be more than enough to turn someone who doesn't know what a mandolin is into a novice mandolinist who knows what further steps he has to take to get better.