Really, I couldn’t stay interested past Dumbledore’s death knowing there was like a hundred ways he might not actually be dead. The whole deathly hallows thing even acknowledged that, it’s good that Rowling very intentionally chose not to do a C.S.Lewis there. But the problem was the inherent brokenness of the world, which was just unsuitable for a serious story.

Underpants. Especially if you have the high ground.

Monopoly was also designed to annoy people, yet somehow people play it hoping it will be fun.

If you were 4 and now you are 44 then you might be an integer variable. If sister is also a variable, we don’t know when she was allocated. She might also be an integer constant in which case she’s arguably immortal.

If your parents had another daughter in the meantime (or if your older brother became female), “my sister” would still be a valid reference, to a completely different person.