Not being much of a fantasy reader, I wasn't a fan of Terry Pratchett's fiction, although I did develop a lot of affection for the man from the times I've seen him on panels and such at science fiction conventions (SF fans being like the ancient Greeks in that our gods walk among us and occasionally meddle in our affairs). Nor am I a huge fan of the late Robert Heinlein, although unlike Pratchett I did read a lot of his books in my youth. But the recent death of the former -- at an age not all that much greater than mine -- got me thinking about the latter.
In Heinlein's 1956 novel The Door Into Summer, the book begins with the protagonist renting a rural farmhouse and living with a cat named Petronius, indeed the very same after which my own feline overlord Petronius is named.
Typical of many rural buildings, the house had been added to over the years such that it had an unusual number of doors leading outside. And like many cats, Petronius was constantly demanding to go outside, even in the dead of winter. The cat insisted on exploring all the doors, all the time, and the hero of the story remarked that Petronius was looking for the "door into summer", the door that lead to the grassy meadow full of butterflies that it remembered from the prior season. (SPOILER ALERT) So at the end of the book when Petronius dies of old age after a long and happy life, the hero says that his beloved cat finally found that door he had been looking for.
I liked that metaphor very much. When it is my time to have that final stroll with Death, I hope my friends say "Chip finally found the door into summer".