LOL - all joking aside, I know a dude who claims he sold a lb. of pot to him in that era - just what a guy who has to run for a living needs.
I also recall a play (against a forgotten opponent) where he turned the corner and smashed a linebacker in the helmet with that same forearm, knocking the dude unconsious for a few minutes. One of the few plays I can recall where a running back got called for unnecesary roughness.
But yeah, he lost his edge pretty quickly after reaching 30.