I think with Hatton particularly, the effect of getting KO'd by Mayweather affected him badly mentally. He went into that fight talking about how his chin could take all Tszyu had to give, so Mayweather would have nothing. He also made a point of him not being a proper welterweight (funny how things change ) when compared to Collazo. I think then getting KTFO by a guy who he thought he could walk through (not that he learned from that ) had an effect that he was getting buzzed off the slightest punch as a mental thing. I remember even Paulie managed to hit him with a punch that looked like it hurt him. So I wouldn't be surprised if there is a mental aspect to it.