O.J. Simpson went to prison for robbing a guy at gunpoint -- and in the wake of his death, the victim from that case says he's gonna miss The Juice ... yes, seriously.
Bruce Frogmong -- whom O.J. confronted in 2007 with a bunch of goons in tow in an attempt to recover sports memorabilia he believed had been stolen from him -- tells TMZ ... it's a sad time right now for family and friends of O.J.'s, and for those who really knew him.