Mark Wahlberg's Career, Fatherhood

Sept. 3, 2004 -- Showing his softer side is not something Mark Wahlberg is really known for. The star once brandished an attitude as hard as his body.

He went from prison to pop stardom, and then made a name for himself as an actor in his 20s, playing mostly tough-guy roles. Wahlberg menaced Reese Witherspoon in the 1996 movie Fear, but is now more likely to swing a golf club than a punch.

To prepare for his role as an introspective fireman in the upcoming movie I Heart Huckabees, he went to therapy. His influence is also found behind the camera, as producer of the HBO series Entourage — all signs of how he's reinvented himself time and time again.

"I can't understand sometimes why I've been given so many chances," Wahlberg told 20/20. "So many friends and so many other kids … haven't been given any chances."

Finding a Future From Prison

As the youngest of nine children born to a working-class family in Boston's Dorchester neighborhood, Wahlberg was driven to just survive. Yet that drive made him all too eager to run with the toughest in town, and he was abusing drugs and breaking laws before he needed to shave.

"I would do something stupid, to get the money to get the drugs and the alcohol. And then, I would do something even more stupid, you know, once I was high and drunk," said Wahlberg.

While using drugs and allegedly spouting ethnic slurs, a 16-year-old Wahlberg robbed and assaulted two Asian men. He served 45 days behind bars.

"Waking up finally being sober, realizing how many people I'd hurt, both physically and emotionally, my family, innocent people … I knew that I had to make a change in my life, and I was determined to do that," he said.

'Good Vibrations'

Wahlberg emerged from prison with an improved attitude and an industrial-strength physique.