He actually had a fairly normal longevity, Cocaine use may have hurt him towards the end. Unlike todays fighter (Marquez, Mayweather Jr. , Pac) he didn't have access or use modern nutrition (ie trt, steroids, etc),. Without those enhancement the aforementioned boxers wouldn't be fighting until mid-late 30's either with the effectiveness they have.
Pea did have good longevity but his performances fell off IMO. He lost his sharpness and his just seemed to lose some focus. I suspect his was doing Coke in the mid 90s and he didn't fall off totally until the Trinidad fight but I think he had been slipping for awhile JMO.
Like many have said, drug abuse, and perhaps just as bad for Sweet Pea was boredom. Once he became convinced that he was in a different league from any other fighter his size, that he could half ass training and still outclass his challengers, his downfall was inevitable. I think a lot of top fighters have that problem, but it's certainly more pronounced for some. (See Ali, who was often guilty of underestimating his opposition, which sometimes cost him, Bowe, etc.)
