My thing is I think we just use the word "prime" too loosely at times to justify a good fighter being beaten by another good fighter on a good night.

How many times was Darchynian "done"? He wasn't done, just got his head knocked off by Donaire.

The Oscar that lost to B-Hop wasn't done, but the Oscar that got retired by Manny was well beyond done.

The Mayweather that fought Berto was done... and we see by the damn exhibitions that he is done. For good. Mayweather may be so in tuned with his body and knows the psychology of the sport that he KNOWS that even if he wanted to continue to have "real fights", he probably would have gotten hurt even if he won most or if not all of them.

Let us not forget: His father, uncles and his best friend, Nate, all have pugilistic dementia or some brain damage. Not so much the youngest uncle, but Roger is suffering now and Floyd Sr. has signs of it and Nate retired form boxing EARLY with brain injury and Floyd has been taking care of him by giving him a job even after his career was over!