(CNN) - Known for his at-times brazen, combative demeanor, New Jersey Gov. Chris Christie opened up in a recent interview about his low point in life, sharing a compelling story about the moment he realized his mother would soon die.
The Republican governor and potential 2016 presidential candidate described his mother as "indestructible" after overcoming a brain aneurism and breast cancer earlier in life.
But later, she was diagnosed with lung cancer that spread to her brain. In 2004, long before he was governor, Christie was with his mother and father when the doctor shared the bad news, the governor said Thursday in an on-stage interview at an educational summit in Las Vegas hosted by the "Knowledge Is Power Program."
"The low point was I got the car to drive her home… I put my hand on the stick shift to back out, and she put her hand on my hand and she said, 'I know I'm going to die.'"
Christie frequently talks about his mother and has described her as someone who was "tough as nails" and "didn't suffer fools at all."
"In the automobile of life, Dad was just a passenger. Mom was the driver," he said in his high-profile speech at the 2012 Republican National Convention.
But the interview offered a rare look into their relationship after she received the diagnoses. The governor said the moment in the car was the first time he had ever heard his mother sound "defeatist."
As the daughter of a single mother, Sondra Grasso raised her two younger siblings after her father left, Christie said. Grasso, who had Sicilian ancestry, was married at 18-years-old "to an abusive guy who beat her," he added. She eventually left and raised three children with Christie's father.
She later became an active force in Livingston, New Jersey, where she lived for 38 years and worked as a receptionist at the Board of Education offices. An article about her from New Jersey's Star Ledger described her as "the district's public face for countless numbers of nervous children who came with parents to be registered for school and were immediately put at ease by her charm."
Christie also held her in high regard.
"This is a woman who I thought would beat anything," he said. "I said to myself, she has been there for every minute of my life for me, and I'm going to be there for her death and I can't let her down."
"I felt like I owed it to her," he added. "I think that was the low point–that point that she looked me in the eye, and I knew and she knew that it was over."
Sondra Christie died weeks later in 2004 at the age of 71.
– CNN's Ashley Killough and Mark Preston contributed to this report.