The Jade Master

A story my girlfriend told me:

In ancient China, when a jade craftsman would take on an apprentice they had an unusual way of training them. First, they would give the young child a piece of jade. Then, the master would read from a book; explaining the history, different kinds of jade: all the book knowledge on jade available. During the time, the young child would probably not listen, and just play with the piece of jade. after a period of time, the master would give the child another kind of jade to play with; all the while he never acknowledged the jade to the child, just read from the book and let him play. After doing this for several years, upon receiving a new piece, the child would suddenly call out "this piece isn't jade, it's just a stone!" At that time the master knew the child was ready to start crafting the jade, now he intrinsically knew the feel of jade, even if he couldn't explain why he knew if it was jade or not.