Nice article and encouraging message to branch out and learn new skills. 20 hours is enough to learn the basics and assess your interest in the area. That is quite useful. 200 hours is a better number to get to some proficiency in my experience.
Agree that 10,000 hours and expert mastery may not really be required or a useful goal in many arenas.
Written by Carl Byington ~ Engineer, Adventurer, Traveler
Adventure, travel, culture, technical, environmental, and fitness. "Either write something worth reading or do something worth writing." ~ Benjamin Franklin