Olympic swimmer Michael Phelps Interview

Olympic swimming stud Michael Phelps said he's learned "the hard way" about betrayal and friendship after a photo of him toking on a bong made him a marijuana poster boy.

In his most candid interview since the secretly snapped party photo was published by a British tabloid Jan. 31, Phelps blamed stupidity for his dive into reefer madness.

"I'll say that there are a lot of people out there who want to take advantage of any situation they have," Phelps told NBC's Matt Lauer in an interview to run this morning on the "Today" show and on "Dateline" Sunday night.