Dos Santos has no reason to apologise for his work in the UFC and needs to do exactly nothing more to prove his brilliance.
He's only 28 years old, and while he's still learning about himself and his sport, he's already put together a Hall of Fame resume.
But dos Santos remains motivated to prove his legitimacy as an elite heavyweight. Maybe because he smiles too much, has never even thought of biting an opponent's ear or threatening to eat their children, he doesn't come across as a prototypical heavyweight champion.
He'll defend his title in the main event of UFC 155 on December 29 at the MGM Grand Garden in Las Vegas against Velasquez, the man he won it from with a 64-second stoppage on November 12, 2011.
A short while after dos Santos knocked Velasquez out at UFC on Fox 1 in Anaheim news came out that Velasquez went into the bout with an injured knee that hampered his training. That revelation has also altered the public perception of dos Santos.
Among some, he's still got to prove his legitimacy as champion because, the theory goes, he didn't beat a fully capable Velasquez.
But dos Santos believes part of the reason for the doubts about him stems from his easy-going nature. Were he more outwardly nasty, such as Brock Lesnar was during his UFC heavyweight title reign or like
"It's a little bit strange, because I feel like part of the problem is I'm a pretty mellow guy," dos Santos said. "People see me as a nice guy. They see me smiling. They see my personality. On some level, I have this feeling that people have this notion that to really be the heavyweight champ, to be this fierce, ferocious fighter, you've got to be a tough guy and you've got to appear mean.
"It's almost like some people sort of want that. It's hard to please everyone. It's impossible. … So many people approach me and talk to me. Kids, moms. The moms tell me I'm a great role model for their kids. They appreciate the way that I am. I have a lot of elderly people approach me. I get a kick out of that. But I do feel at some level, it's never going to be enough and it's going to be impossible to please everyone."
Generally, professional athletes will fight to the death to win a game of checkers, let alone a sporting event at which they make their living.
Clearly, that competitive streak exists deep within dos Santos. Though he would never say it, he badly wants to knock out Velasquez and silence critics who believe he won the title from a guy not at his best.
His competitiveness also extends into the endorsement space. He's one of three mixed martial arts fighters, along with UFC light heavyweight champion Jon Jones and middleweight champion Anderson Silva, to be sponsored by Nike.
Dos Santos is also sponsored by TNT Energy Drink, Corinthian Sports Club and CERS. He's learning English so that he can communicate not only with more of his fans but also potential sponsors.
Ana Claudia Guedes, his representative, said there has been a significant increase in sponsorship interest in him. She said part of it is a result of being the champion, but more is the result of his personality.
Sponsors are desperate to steer clear of controversy, which is why dos Santos is becoming increasingly busy away from the cage. He's squeaky clean but remains one of the best fighters in the sport.
"A guy like Tyson invoked a lot of respect and a lot of admiration for his athletic ability," she said. "But with any combat sport, there is this issue of concern, because some people don't like [combat] sports because they consider it violent and they go, 'The world is violent enough already.' When you have a figure behind it who was perceived as aggressive as Tyson was, it fed into those concerns.
"Junior's personality is the antithesis of that. It's very clear that his fighting is an act of athleticism and couldn't be further from an act of violence. There's not a violent bone in his body. There is not a violent thought in his mind."
He still doesn't believe, though, that he's gotten the respect that his championship and his accomplishments should accord him. He's 15-1 and has beaten a who's who of the best in his division, yet he somehow feels less appreciated.
The UFC heavyweight champion has shown his talent time and time again over the last several years with decisive, one-sided victories over elite fighters Cain Velasquez, Frank Mir, Shane Carwin, Roy Nelson, Gabriel Gonzaga, Mirko "Cro Cop" Filipovic and Fabricio Werdum.
About the only thing he hasn't done is knock two guys out at once in a handicap match, but he still remains unsatisfied.
"I think it could be a little better and I thought I would have gotten a little more recognition," he said.
"… I think maybe my expectations were a little higher. I thought I'd be a little more recognized [than I have been] and [perceived as] a little more important. I thought I'd receive a little more prestige from people and from the UFC also. Maybe my standard was a bit off, but I'm happy with where I am and where I'm headed."
A second win over Velasquez – a healthy, in-shape, fully prepared Velasquez – may forever change the perception of dos Santos.
He'll be able to smile all the way to the bank after that.