[rargulati]

That's incorrect. The GP comment (tinco) is simply relaying a story that says that Google should know that he and his significant other have disjoint interests and query patterns (though they share devices and location). It's an anecdotal story. Someone else could have said that they like things in the join of the two interest sets and dislike something else. Tinco's story helps us learn more about the "entangled session" problem - a known area of research in Google (per the constructive response from nostradamons). Claims aren't made about how to go about doing that (people searching for X will never search for Y), just that Google should have a way of addressing Tinco's specific case.