Howard Bryant on the New England great:

On a micro level, Moss is perhaps the most physically gifted receiver in the history of his position: bigger and faster than Jerry Rice, the best receiver of all time, but with outstanding hands and physical ability. But Moss doesn't play the game with the every-down ferocity of Hines Ward or the stoic, grinding execution of Rice. He is more mercurial. Oftentimes, it is obvious by his body language lining up whether or not a given play is designed for him, and when things are not going well, that leaves him open to the charge that he doesn't care.

The older I get, the more I think the mental is, in fact, physical. Maybe Jerry Rice was wired to be Jerry Rice. Coaching helps, but it can't rewire you. Expecting Moss to be Rice-like, might be almost as illogical as expecting Rice to have run as fast as Moss.