Just had a thought about how this whole skill thing works, relating to the statement that some people have to practice more or less time than others to achieve the "same" resulting output.
In RPGs, it's common for class distinctions to be made, and in some cases, certain perks come with leveling up as per your class. Some people start to really "get" things after a certain level, and then the growth rate per level, that is, the rate of bonuses per levelling up, also increases drastically, if not exponentially. I could totally believe that art is a skill like that, because if nothing else, we all have our niches. Legos art, Suuper's art, and my art all have vastly different qualities, and in those qualities, or, if you will, within our own styles, we are our own "budding masters".
The reason I think it might be so difficult to put things into "level" boxes is because every person is a class in their own right. I personally feel like I just leveled up with a doodle I saw last night, which makes sense given how close I am to level seven, but my level seven is different from Suuper's and Lego's level sevens, which are different from each other.
It may seem kind of obvious, but I thought I'd share my little mini-epiphany.