Olly didn't really care who any of those people were. They all invented boring things that were of no use for him. Okay maybe perpperup potion was useful to a lot of people so that was alright. And it was hard to imagine a time before floo powder was invented because it was so normal now. He could admit that those things were useful, but he had already forgotten the names of the people who had invented them. Maybe he should have written them down as soon as he heard them so he wouldn't forget. Oh well, he could look them up later if he really needed to. He did remember Bertir Bott though. Of course! That man did some good. He made candy, and that was important.

Necessary for an invention? Everybody was already giving pretty good answers so he wasn't sure at first what else he could contribute. But then he thought of something and raised his hand. "The thing they were inventing would have to be useful. I mean what's the point of inventing it if there's no use for it? And if they want to sell their invention is has to be something that someone else would want to buy."