Brown also reacted to Rihanna's comments from her exclusive interview with ABC News' Diane Sawyer, when the pop star broke her silence about the night Brown beat her.
"I know that he felt really bad about doing it. I just didn't know if he understood the extent of what he did," she said in the "20/20" interview. "The thing that men don't realize. When they hit a woman, it's -- the face, the broken arm, the black eye. It's gonna heal. That's not the problem. It's the scar inside."
Brown told Roberts he understood Rihanna's remarks about the wound that does not heal.
"I can, I can see what damage it does, mentally, more than physical," he said.
Brown has talked about domestic violence in his own family. On the "Tyra Banks Show" in 2007, he talked about the abuse his mom suffered from his stepfather, who has always denied the charges.
"He forgot the pain that he witnessed with his mom. Fame came to Chris very, very young. At a very young age, so with fame comes a lot of things and the most dangerous thing is the freedom. No limits. No boundaries. You're a kid and the word 'no' doesn't exist," Rihanna said.
Brown said it was difficult to hear his former lover's remarks.
"It's really difficult. ...And it kind of -- it hurts. But it's just -- it's just something that I have to be responsible for, because I'm responsible for my actions," he told Roberts.
Brown, 20, pleaded guilty to felony assault and was sentenced to five years of probation, community labor and one year of domestic violence counseling. He said the classes have helped him control his emotions.
"In this class, I'm not saying necessarily teaches you how to love, but like those emotions that get mixed up when you just in love or just whether it's jealousy, insecurities, whatever the case may be in -- in relationships. They teach you how to control a lot of -- certain things," he said.
The couple briefly reunited three weeks after the assault in Miami and Brown wrote the song, "Changed Man," for Rihanna as a plea for forgiveness. The lyrics refer to the turmoil that struck their relationship.
"What do you do when the truth isn't quite enough/ They looking at you telling you that we need to break it up/ You need to do what you do, it's me and you in love/ But I'mma make it up to you and show the world I'm a changed man," he sings.
While Rihanna said that she has not heard the song, Brown told Roberts that he played it for her a month after the incident and she cried.
"I played the song for her. ...The day I did it...a month after the situation," he said. "She called when she first heard the song. And I mean, I'm not trying to say -- call her any liar or anything like that. But I played the song for her when I first wrote it. And she cried."
The couple officially broke things off in March 2009. A restraining order requires Brown to stay 100 yards from his former girlfriend for the next five years, unless they are attending music industry events.
Brown told Roberts that he still has "love for" Rihanna, but there are no words left.
"I've said like everything that I can with me and her. Me and her have talked. Me and her have spoken about the situation," he said. "And she knows how sorry I am."
Despite the public scrutiny, Brown said it has made him into a stronger man.