I haven't been following this avidly so sorry if it's already been asked. Can anyone who's bought "Spare" say whether and how the title is brought up in the book? On another social media platform some people were discussing the phrase "an heir and a spare" as if it was a cruel thing that Charles thought up, whereas I know it as a common, old jokey saying about families that have anything to inherit - a saying that I could imagine being used by royals jokingly. What was the context here?