"Bad and stupid judgment and something I'll always live with, and a lesson I'll always learn from," Phelps said. "Mom wasn't happy, obviously she supportive, through it, but wasn't happy."
Since his record eight gold medal wins last summer, Phelps has been awash in endorsements -- and adoration. But this week, America's sports hero became a late-night punch line
Host David Letterman said: "unemployment's high … Michael Phelps is high."
He lost a deal with cereal maker Kellogg's, faced a possible criminal investigation for drug use and was handed a three-month suspension by USA Swimming. The suspension, they said, was because he disappointed so many people, particularly kids.
"You know it's fair, you know, obviously from mistakes you should get punished," Phelps said.
It's the second time Phelps has had to apologize for his behavior. He was arrested for drunk driving in 2004.
This time, young swimmers are divided.
One young swimmer said: "As a person, he needs, just like everyone else does sometime in their life, to just get their head on straight."
Except he's the face of a young sport - and he's worth a reported $100 million in lifetime endorsements.
When a sport is trying to get out of its fledgling state in tional popularity, fort to have someone to lean oN. And he's supposed to be the one," said Andy De Angulo, the swim coach at Ransom Everglades School in South Florida.
On his Facebook page, most fans are standing by him as are most of his sponsors. Some in the anti-drug community see this as an opportunity.
"Actually, it's an opportunity to talk about, do we want our kids using drugs," said Steve Pasierb, the president and CEO of Partnership for a Drug Free America.
"I'm back in the water and doing the thing I love," Phelps said.
And, he hopes, leaving this latest controversy in his wake.