His case to young athletes today who face the same choice he did two decades ago: With modern training techniques, legal supplements and nutrition, you can compete clean and run just as fast as the cheats.
"If you believe in that, you eat properly, train properly, get enough rest, don't drink," he said, "you can achieve your goal and not use performance-enhancing drugs. It can be done."
Johnson's own experience reminds why it can be so tough to keep that faith. He was encouraged to use steroids by a coach he idolized, swept up in the mindset that everyone was doing it and he needed to keep up.
Pure Sport is pushing for the creation of an independent council that can advise athletes who are tempted to dope. Johnson insists that maybe everything would have been different had there been someone to confide in.
Sitting next to Jose Canseco under the artificial lights of a hotel conference room, Johnson spoke on a panel Wednesday about how to rid sports of PEDs. One moment he would sound at peace about his past, the next bitter. He takes full responsibility for breaking the rules but also feels singled out in an era of rampant doping.
The positive tests keep coming today. The past several months alone, the big names in sprinting included Tyson Gay and Veronica Campbell-Brown. In an interview after the panel, Johnson said, "There's nothing new."
"The excuses have all run out," he added.
And even if he understands why athletes still make the same choices he did, he has a simple reasoning for why they shouldn't.
"This is the temptation that we face every day in life," Johnson said, noting that people are able to resist those other urges to cheat.
