How we cite our quotes: (Chapter.Paragraph)
Quote #1
"Minds hold more than they know," the tall man said. "Particularly yours. And what else have you to say?" (3.21)
Brains are strange and wonderful things, but in Will's case, his mind knows an entire language and facts from history that he doesn't even know he knows yet. The Old Ones value knowledge immensely; the more they know about the world, the better their chances at defeating the Dark.
Quote #2
And with Will beside him he strode long-legged round the hall, holding the candle aloft again and again beside each of the hanging tapestries on the walls. Each time, as if he had commanded it, one bright image shone for an instant out of each glowing embroidered square, as bright and deep as a sunlit picture seen through a window-frame. And Will saw. (3.64)
The Old Ones show something of themselves to Will, and he knows who they are instantly. Even though he's only just learned about his magical powers, he's able to use them right away. It's like he already knows or something.
Quote #3
"It is the third Sign, Will. The Sign of Wood. We call it sometimes the Sign of Learning. This is the time for remaking the Sign. In every century since the beginning, Will, every hundred years, the Sign of Wood must be renewed, for it is the only one of the six that cannot keep its nature unchanged." (6.6)
The Lady tells him that the wood has to be renewed from century to century, which is interesting since it's also the Sign of learning. It's no coincidence that the two of these are combined. Think about it: Learning is something that also has to be renewed and replenished from time to time to keep the skill active. Use it or lose it.