I think the advantage of starting when you're young is that you have to get the job done with limited strength in your hands. The weight of the club was too much for young Rors as a kid. He learned the optimal way to use his body to swing that club accurately and powerfully before he even knew what he was doing. Gravity and the club and the ball and the ground taught him how to do what he does.
One of the guys on my basketball team has a 5 or 6 year old kid who can drain shots with a official sized basketball on a ten foot rim all day long. Little man is only 3 feet tall. His form is absolutely perfect. His elbow is perfectly under the ball. His release is vertical and he uses his feet and legs to power the shot. If he sticks with that formula he'll be a fantastic shooter. Little guy makes it look easy because he's not trying to fight the most powerful forces involved in his task.
So much of my learning about golf on SITD has been to discover what really happens in the swing. When I get out of the way of the swing and learn to set it up the most powerful way, I'll be closer to understanding what Rory knew at age 8.
Rory's not perfect but he's got a great move and he's fun to watch for sure. I hope he doesn't let fame get to him like it got to Tiger.