I think it's because he can see other peoples brains quickly and...

I think it's because he can see other peoples brains quickly and easily so pigeonholes them, no mean feat for someone untrained in such things and even for many trained, or if he just picked it up over time. When you know the what for's and why's after a while all those identifiable as what trump would call a name look the same because largely they all actually are.

Don't discount a person(who must have something first though) who has never drank alcohol in their life most esp before the age of 30 say...because people only live one stream so to speak they can never know what higher abilities in affect and consciousness that remains begging all the way to the grave that otherwise would never have all because of earlier silly behaviour.