Johnson, 43, describes a scary situation when he was 15 that involved his parents.
One day Johnson, his father and his mother went out to lunch and they "got into a very big fight ... just really loud arguing," Johnson says.
His mother and father got into one car to leave, and he drove in another, following them on the Interstate.
"Their car starts swerving, and I can clearly see they are arguing," he says in the clip.
His father pulled over to the side of the road, and his mother got out of the car, Johnson says.
"She had a glazed look over her eyes that I had never seen before," he says. "And she walks right into the middle of I-65 and continues to walk down into incoming traffic. And my heart stopped. Horns were blowing, and cars were swerving out of the way."
Johnson got out of the car he was driving and grabbed his mother.
"I don't remember what I said to her. I remember she didn't say a thing," he continues. "In that moment, one of the greatest lessons I've ever learned was how precious life is and in an instant, it can all go away."
He adds, "The irony is my mom has no idea that it even happened ... She does not remember anything, thank God."
Johnson's parents divorced in 2003.
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