Retirement usually means hiatus. I respect the hell out of fighters who keep their word about retiring e.g. Finito Lopez, Hagler, Marciano.
Here's a question I'm curious about What ruins a fighter the worst? What is most detrimental? Long bouts of inactivity? Ballooning up and down in weight? Simple wear and down, wars of attrition, "mileage". Purely age related, not being able to pull the trigger and react anymore. What dooms most fighters?