This post was originally published on People.com.
He’s the most decorated Olympian of all time, but don’t think for a second that growing up as Michael Phelps was easy.
The 31-year-old swimming superstar —and new father — opened up about his struggles with ADHD in a new video for the Child Mind Institute‘s Speak Up for Kids campaign, explaining that a teacher once predicted that the Baltimore native would never succeed.
“I [saw] kids who, we were all in the same class, and the teachers treated them differently than they would treat me,” he says. “I had a teacher tell me that I would never amount to anything and I would never be successful.”
Phelps, who has earned a whopping 23 gold medals during his Olympic career, said he’s lived with ADHD “my whole entire life, and it’s something I continue to live with. It’s changed my life since the beginning.”
“Growing up, I was someone who was constantly bouncing off the walls — I could never sit still,” he says.
But he has since found a way to cope with his condition.
“I think the biggest thing for me, once I found that it was okay to talk to someone and seek help, I think that’s something that has changed my life forever,” he says. “Now I’m able to live life to its fullest.”
Phelps joins celebrities including Emma Stone, Lena Dunham and Jesse Eisenberg in recording deeply personal videos about their struggles with mental health and learning disabilities — conditions that affect 1 in 5 U.S. kids.
Dr. Harold S. Koplewicz heads up the Child Mind Institute campaign and tells PEOPLE that these celebrity videos help to decrease the stigma surrounding these conditions — and let kids and their parents know that they are not alone.
“The reason I think they’re so inspirational is that all of us start out as kids. When you’re a parent and your kid is inattentive, or more anxious or sadder or learning disabled, we worry that it’s going to be awful and sometimes we’re so ashamed that we don’t speak up,” he says. “Here are these remarkable individuals who give a message that says ‘If you are not ashamed, if you speak up, if you get a diagnosis and if you get treatment, your life can be as full and as productive as anyone’s if not even more so than some average people.’ ”
Phelps says that although his ADHD was “a challenge and a struggle,” it also made him the person he is today.
“It’s something that I’m thankful happened, and I’m thankful that I am how I am,” he says. “I look at myself everyday and I’m so proud and so happy of who I am and who I was able to become.”