Everyone takes head trauma differently. Bowe and Vargas weren't in as many ring wars as Gatti, but both guys seem pretty slurry at this point. Come to think of it, James Toney has taken a lot of hard shots as well.
i think there must be a rule saying you cant fight after a 20 year career or somthing like that. or only fight in extreme cases. i wouldnt mind a 40 year old world champion it's only the agility and speed to get out of the way of punches that worries me. jerry quarry was a great agile fighter with a big rigth hand and left hook who was a counterpuncher....then became a boxer slugger ythen just became a mauler which tarnished his career.