agreed you simply cant. not only do do different people simply react differently to external stimuli but you are only seeing a snippet of information and trying to extrapolate how someone feels overall from that literally a clip of a few seconds (if that). best just to avoid those sorts of "conclusions" i remember when goff was a rookie and standing on the sidelines, lots of posters were pointing out that he was "disinterested" in the game because he was not "acting" they way they thought he should.
