"I'm a very strong individual," he said. "When you have a set of ideals and make them really well-known, people either like them or they don't."
When told he ranks with Hulk Hogan and the Rock as one of the most popular wrestlers ever, Cena remains humble.
"That's pretty important company," Cena said. "I just really love doing what I do and anyone who comes to the Con or the show will be able to see that."
It's hard to imagine that this man who seems to have it all was sleeping in his car when he first arrived in California, but Cena said his journey from then to now has been "fast."
"A lot's happened," he said. "Physically, I'm just getting started. There's plenty left to do. Every day is another opportunity. So it's been a long and great ride."
It's a ride he feared he would continue taking without his 70-year-old father, unless his dad started taking care of himself. So Cena devised a plan for his father to get healthier, starting with diet.
"Once my dad said he was all for it, it was easy," Cena said. "But the initial conversation was tough. But, because my plan is extremely easy, everything worked out . . . and here he is on his 70th birthday, 53 pounds lighter from when he started.
"We were always very close, but that brought us closer."
The day, too, is drawing closer to when Cena will stop wrestling. He says that although he has done a few films, he does not see himself going in the direction of the Rock.
"Oh, no," Cena said. "Dwayne? There's only one Dwayne Johnson. I'd like to be myself, so I'll find a path doing something. I don't know if it's going to be filling his shoes. He's set the bar pretty high."