The only way Thr Rock keeps the name, and the rights therein, is if it is determined that it is a self-made, that is, he was the reason the name sticks in people's minds. You associate 'The Body' with Jesse Ventura, and 'Hitman' with Bret Hart (I remember the time when the announcer first announced Bret's adopted nickname. It was met with derision, as many people knew about Thomas Hearns). Also Hulk Hogan and derivative names with Terry Bollea. Peter will want to have a say about Dwayne Johnson being known excusively as 'The Rock'.
I, personally really liked the Kurt Angle "It's Ture It's True" book. Made me respect him FAR more as a legit athelete. Unless you are a die hard Memphis fan, stay away from Jerry Lawler's "Sometimes its good to be the King".