I am leaning toward the Freddy333/Fashion/Economic times dictates camp for 'the average sized individual' (I agree with By-Tor that a 36mm would look strange on a large athlete/body builder, etc.)
Like anything, there are fashion forward individuals, and then there are late adopters, or 'who cares' crowd.
However, the only thing I would add is, what is still acceptable, semi fashionable (big watch, average build)-- may not be right 'for the times'. We are in tough economic times many places, and the large, look at me, bling, might send the wrong message. Contrast with a 'classic', unassuming, even vintage piece.