A Hat Full of Sky by Terry Pratchett (Discworld 32)

“Why do you go away? So that you can come back. So that you can see the place you came from with new eyes and extra colors. And the people there see you differently, too. Coming back to where you started is not the same as never leaving.”

The thirty-second Discworld book is also the second Tiffany Aching book. She’s a bit older now; eleven instead of nine, but she still has a lot to learn as an aspiring witch, so Miss Tick arranges for her be trained by another of their number outside of the chalk where Tiffany lives.