Here Maybe?

so don't get too comfortable.

I'm sure that I'm far from the the first person to notice that this line in Wintersmith (2006) was published just a year before Pratchett's 2007 announcement of his posterior cortical atrophy diagnosis.

Out of nowhere, Roland, a boy who in this book also happened to acquire specific additional traits like glasses and a love of books, suddenly has a deep, angry hatred of anything which takes memories.

The above line hit me like a damn train, and then I skipped back and reread the sequence as Roland and the Feegles arrived and realised that the Underworld Roland is in is filled with confused old people being parasitised by 'bogles' which steal their memories and identities. It's not remotely subtle but also heartbreaking in how understated it is. The strangeness of the woman dragging a cardboard box is nightmarish. This is actual horror.

Terry. Oh my god. Sir. This is one of your children's books and you brought this here. You brought this here because you trusted and respected your young readers with something so hard and personal. This is Terry writing down his deepest fear, in a children's story, the safest place to put the most frightening things you can think of.