He's 55 years old. Hard to believe.
Sandycoug posted earlier that BYU fans who dislike Johnny Manziel and like McMahon are being inconsistent. While I agree that there are some similarities between the two, I think there, are also some key differences. Jimmy Mac was a little cocky and brash, and yes, he was a bit of a rebel, but overall, I think he was a better guy and teammate than Manziel.
For example, I don't remember reading about Jimmy Mac hanging out with supermodels and partying in Vegas every weekend. I don't think he ever flipped off an opponent. Yes, he did moon some reporters who were flying overhead in a helicopter, but I don't think that's quite the same thing. And, contrary to popular belief, he never called the women in New Orleans sluts. From what I've heard about him, he was a devoted husband and father. (and yes, I know he's divorced from his first wife now. Very few people know why.) Also, McMahon's teammates loved and respected the heck out of him. I also don't remember Jim McMahon bragging that he was going to win a Super Bowl when he first came into the NFL.
McMahon just seems more likeable to me. Yes I know he was a punk, but gosh dang it, he was our punk and he helped put BYU football on the map.