PHILADELPHIA - A recovering drug addict with a long rap sheet who was hailed as a hero for jumping onto subway tracks to rescue a man who walked off a platform deflected the praise Friday by saying he was just doing the "right thing."

Still, Christopher Knafelc suggested that he views the good deed he did, and the praise that followed, as another sign that he is on the right path in life.

"It did help reinforce that I'm a good person," Knafelc told The Associated Press in an interview at his mother's south Philadelphia apartment. "I questioned that a lot because of my colorful past."

Knafelc, 32, had just sat down to wait for a train at a north Philadelphia station on Thursday afternoon when he saw a man flail and fall off the platform and onto the tracks. He said he instinctively jumped down to help, knowing that a train would be arriving in a few minutes.

He called up to people on the platforms to get the trains stopped and he held the man's head and neck stable until firefighters arrived. Train traffic was halted.

"I don't see it as being heroic. I just see it as doing the right thing," Knafelc said.

Knafelc said he has battled substance abuse - including heroin and the powerful pain drug Oxycontin - since he was in middle school in Baden, a small town outside Pittsburgh, and spent years in and out of rehab.

"I created a pretty deep hole to come out of," he said.

Court records show Knafelc pleaded guilty in 2010 in Pennsylvania to charges of theft, driving under the influence, child endangerment and driving without a license. Two years ago, he came to Philadelphia, where his mother and a cousin live, to get a fresh start, he said.

He said he has been sober since 10 days after his daughter's birth in July 2010, when he picked her up from her crib and she smiled at him.

"That was the most powerful thing I've ever felt in my life to this day," Knafelc said. "It was better than any high from drugs."

Southeastern Pennsylvania Transportation Authority spokeswoman Jerri Williams said she spoke with Knafelc soon after his heroics.

"He's clean and sober for about 2 1/2 years but still trying to get his life together," she said. "I think by doing this good Samaritan deed he's kind of surprised himself."

Williams said she saw that as Knafelc recounted the incident on the tracks, "I could see the light go off, the a-ha moment" when he realized that after he was helped by many people in his past, he was able to finally help someone else in return.

"This almost instinctive move to save this guy made him see 'I am a good person,'" Williams said. "It's amazing. This incident may be the start of really good things for him."

Knafelc agreed with that assessment, and he connected the help he's been given by family members to survive his addiction with the favor he did the man on the tracks Thursday.

"I'll never be able to repay them, financially or any other way," Knafelc said. "The next best thing I can do is pay it forward."

Investigators do not know what caused the man to fall on the tracks. Surveillance video shows him walking slowly toward the platform's edge and then over it. He was taken to a hospital and listed in stable condition.