Something needs to capture way more channels of information about you
than you normally bother paying conscious attention to. At least not at
the same time. What people have been saying around you recently; what
clothes you're wearing; what's on your bookshelf; all the people you
know; all the subjects you're interested in; all the projects you're
working on. And something needs to be matching all these items with
other people's items, and items in your surroundings, as a background
process.