FORT WORTH, Texas — There are countless theories and half-truths that exist about the 1990s Dallas Cowboys, starting and ending with a friendship that can’t quite be defined, yet remains inexplicably fascinating. From his home in the Florida Keys, one half of the Jimmy/Jerry duo sounds as if he is in a wonderful place, not only geographically but with his entire life. Jimmy Johnson does want to clear up one misconception, and put to rest a fan/media theory that has only grown over these last few decades. There is the theory that Jimmy Johnson does not want to see the Dallas Cowboys succeed, certainly not win a Super Bowl; that he privately takes joy in the fact that team under Jerry Jones has not won a Super Bowl with a team that he built. "No, that’s not true," Johnson said Tuesday in a phone interview. "The Dallas Cowboys are a big part of my career, and I want them to be successful.