“It’s one thing to look back and regret what happened in terms of growing up, being addicted to internet porn,” he said. “You might look back and be like: ‘Oh, man. I was a loser. And if I never watched it, my life would be so much better.’ And maybe that’s true. But at the same time, the fact that I was addicted to internet porn, the fact that I was so mediocre, makes me uniquely qualified to help humanity.”

In recent years, Mr. Rhodes has emerged as a spokesman against a “disease” that hasn’t been officially recognized by the medical establishment. He seemed uneasy with his new status.

He was careful with every word and asked to go off the record more than a government official. He would not confirm whether he was involved with someone, saying only that, since giving up pornography “for good” in 2013, he has been able to have meaningful relationships with women.

In some ways, his story is that of the digital age. His father was a computer programmer, and he was exposed to digital technology from early on. He gravitated to Nintendo Game Boy and eventually moved to the Nintendo 64 and Sony PlayStation.

At 11 or so, he said, he clicked on a banner ad by mistake and found an image depicting rape. By the time he had reached adolescence, so had the internet, and Mr. Rhodes came to rely on high-definition pornography that was easy to find and often free. By college, he was masturbating while watching it up to 14 times a day, he said.