Fighters who kept climbing after what could have been their psychological Everest?

Joe Louis is an obvious example.

He just kept doing it until his body wasn't capable any more!

 

JCC, Duran, FMM, come to mind and today I see Loma,

 

Pac went from 105 all the way up and cleaned house along the way .. Jofre was an extremely popular sports figure in Brazil and probably only 2nd to Pele at the time from what I've read. there was huge demand for him to keep fighting and I sense he might have felt it as sort of his duty to his country( I'm sure @ChrisJS will correct me if I'm wrong here) and him coming out of retirement and going on that run to win another title was impressive. Bhops longevity was impressive as well schooling Pavlik at 43 years old

 

I get the idea behind the thread..it came from the Frazier thread.. however I think some of the examples you've given are very subjective.
You say Ali's peak was Foreman and he couldn't match it after ? I suggest that was age and wear and tear rather then motivation.
You could say he wouldn't be motivated after Liston but he was.
Tyson was demotivated after Spinks ?He was on a slippy slope due to his life away from the ring , the Spinks fight was an irrelevance in that regard.
Liston wasn't demotivated after Patterson , he was ageing and became inactive because he'd mopped up the division then ran into young Ali.
These guys didn't slide because of demotivation.
A few ( like Lennox ) just keep going until they know they can't anymore, he was one of the best examples of going when the time is right . Very few do which is the real answer to your post. There's a difference between staying motivated forever and a day ( eg Holyfield , which leads to fighting past the point it's good for you) or walking away at the right time ( Marciano / Lennox).

 

Floyd Patterson perhaps?

He really won in the longevity game, despite his size/style working against him.

Perhaps he never truly hit his Everest?

 

I guess that no potential Everest could ever satisfy him for long, and he always had a nagging self doubt!

 

Jofre’s comeback aged 33 came after he’d done some exhibitions with his aunt in some circuses. Apparently he looked really good still and his son asked him “what do you do for work” so Jofre came back.

When he retired for good in 1976 he had another title in mind but after his dad died in 1974 he said he “died a little too” and then his brother Dogalberto was training him in 1976 and then he died of cancer too so Jofre just couldn’t find the motivation again.

 

In the modern era Holyfield, Hopkins, Floyd Mayweather , Manny Pac and Wlad Klitschko have all been total pros who never turned up in less than optimum shape for any fight despite their previous successes. A credit to all of them.