I'm actually not entirely sure about that. For example, if I know a lot about a particular topic and the search engine knows that I know a lot about that partic

I'm actually not entirely sure about that. For example, if I know a lot about a particular topic and the search engine knows that I know a lot about that particular topic, then when I search for something, it should give me a condensed result and not introductory-level material. Or if I have certain preferences for the format of material I'm given. For example, if I prefer college-level outline material versus eighth-grade reading level text, for example. So it seems entirely reasonable to me that you would get different results. If I had a personal assistant that was performing the search for me, I would expect customized results from them. I don't know why I should not expect the same from a machine.