There are definitely some political things that I would want to delve into, some conversations that I would want to listen to as a fly on the wall.
Other things? Sometime, I wish I could observe what my cats do all morning while I’m at work. I know people have cameras for that sort of thing but I don’t feel like going to that bother.
I think the tendency for most of us is to want to be aware of conversations that are happening when we’re not around that might be about us, but think for a moment if you would really want to be privy to that. If you’ve ever read Voyage of the Dawn Treader by CS Lewis, there’s a place in the story where one of the characters, Lucy, has access to a book of magic spells. And one of the spells is to find out what your friends really think of you. She can’t resist the temptation not to read it even though she has the singular purpose of finding one particular spell, so she reads this spell and immediately can witness a conversation on a bus between two of her friends. She finds out that one of them apparently doesn’t think as much of her as she thought she did and because of that, the friendship is ruined. But then when Aslan is talking to her about the whole situation afterwards, she tells him that she wishes she had never witnessed the conversation because now she will never be able to look at that person the same way again. So be careful what you choose to witness as a fly on the wall!