The ghost of Don Shula disagrees.
If nothing else, I have lived an interesting life and have some good stories. I knew a guy who played in the NFL for over a decade and his last stop was with the Dolphins. During Dolphins' training camp, Shula was a fitness nut and would force the team to run "The Shula Mile" with him every year. My acquaintance was nearing the end of his career and this was his first camp with the Dolphins and Dolphins' players warned him, "Whatever you do, don't beat Shula in the race or you'll get on his bad side." So they're nearing the end of the mile and this guy says "F*ck it. This is ridiculous. We're basically jogging and not running. I'm going to beat Shula." He did and a few days later, he saw his name on the waiver wire. Like I said, it was the last stop in his career and when he told the story, he couldn't stop laughing.