The Masked Singer runner up Charlotte Church says she feels "sorry" for going off the rails aged 16.
In 2002, after being caught smoking, Charlotte moved out of the family home aged 16, and cut off contact with her mum and stepdad and began partying.
Mum Maria admits she had a nervous breakdown as she was so "devastated" as the breakdown of their relationship.
Speaking to Kate Garraway on Life Stories, Charlotte, now 35, says: "I don’t feel guilty as I don’t believe in guilt as a worthwhile emotion. I feel sorry - particular to my mum - knowing what it cost her."
She explains of the turbulent time: "I needed to be free. I had to be a specific way for a long time, and all the normal ways we grow, how puberty happens and how girls become women were stifled.
"I felt I had to be this eternally young, innocent little girl. That’s not where biological life was taking me. I had to cut the ties.
"I was at an age where I thought I knew everything.
"They were trying to protect me but I felt they were holding me too tight. It’s only with hindsight I knew what it meant to my mum. They felt they’d completely lost me."
Maria says she understands Charlotte felt like she had been in a "pressure cooker" and "wanted to explode" while travelling around the world working while completing her studies at such a young age.
"She just went bang," she adds, of Charlotte leaving home. "I was hurt. I felt lost and isolated."
Elsewhere in the chat, which airs tonight at 8pm on ITV Charlotte says one obsessed fan collected her shoes, and another fan believed her singing cured his illness.
*Kate Garraway’s Life Stories featuring Charlotte Church airs tonight (Thursday) at 9pm on ITV and ITV Hub.