That part isn't the surprise. Anyone who watched the Chiefs play in 2013 realized his worth to his team.
You probably don't realize the other part of this -- just how much a holdout would have hurt Charles. It would have hurt Charles plenty, perhaps as much as his absence would have hurt the Chiefs.
Though it may appear otherwise now -- after his arrival at training camp at Missouri Western State University was delayed by a couple of hours until he received the contract extension he wanted -- Charles isn't a greedy, me-first diva. He is by all accounts a good teammate. Despite his desire for a pay raise, Charles attended offseason workouts and practices. It wasn't just a show of good faith to the Chiefs. Charles wanted to be working and sweating with his teammates.
Charles cares about giving the Chiefs their money's worth. He cares about what his peers think. He cares what you think.
It's important to Charles to leave an imprint on the game that will last for years. He's well on his way toward doing that. Many backs have had a season or two as good as the ones Charles has put together in recent years.
Few have had as many as Charles. Playing in coach Andy Reid's offense for the Chiefs, Charles has a great opportunity to enhance his legacy, but that would be impossible for him to do if he's sitting out in a pay dispute.
So if you think the Chiefs were relieved to see Charles take the practice field as they opened training camp Thursday, know that the feeling was mutual.
"I didn't want to hold out," Charles said. "That's not my place. I couldn't do it. I just wanted to get the deal done. I could have held out and gotten [more money]. I'm just happy with what I have for right now. ... I didn't want to even be selfish like that. That's not my personality."
Charles joined the Chiefs at camp a couple of hours after the reporting deadline on Wednesday, after the sides had reached agreement on the contract extension. He felt ashamed enough about a holdout even that brief that he took to Twitter with the joke he had been late because his car broke down on the way from Kansas City to St. Joseph.
So while the Chiefs needed Charles, the opposite is just as true. And had the Chiefs held firm for just a few days and held back their offer of new money, Charles might have caved first.
"I couldn't [hold out]," he said. "I wanted to do it but it's just not me. I'm not a cocky player. I'm not one of the players [who does] that to his team. I've always been a team player my whole time here. I was ready to get the deal done and move forward."