The 30-year-old American, expecting his first child with fiancee Nicole Johnson in May, speaks movingly of impending fatherhood and how it has given added resonance to a renewed relationship with his own father – one of the benefits of treatment he underwent after a second drunk-driving arrest in 2014.
At swim meets around the country, sponsor's junkets and, this week, at the US Olympic Committee's pre-Rio Media Summit in Los Angeles, Phelps has touched on the kind of personal matters he once shied away from in interviews.
"I want to show people who I am," Phelps said. "They've seen me as just a swimmer."
What the public makes of the real Phelps is up to them, he said.
"To be quite honest, whatever opinion you have of me, that's fine. I am who I am, and I'm not sugarcoating anything."
But Phelps, whose record 22 Olympic medals include an astonishing 18 gold, isn't giving away the game plan for Rio.
As in the build-up to the Athens Olympics, his sensational eight-gold campaign in Beijing, and what he once expected to be his last Games in London, Phelps won't confirm just what events he's aiming at in Rio.