Actress Tatum O'Neal was just six when she first tasted alcohol, while hanging out with her mum and her 15-year-old boyfriend.
The Paper Moon star has always been open about her troubled childhood, which she claims involved suicide attempts, drugs and booze, but revelations in a new book are sure to shock fans.
She recalls her first party experience was with her mum, Joanna Moore, when she was just a little girl.
The actress tells U.S. news show Access Hollywood, "We were living in a very kind of unsupervised place with my mom; she was really not doing well. She had had a very terrible bottom with speed and alcohol.
"My mom... was with a 15-year-old boy... She was probably 35. That was a terrible situation.
"There was a lot of alcohol around and there was a lot of other things... and I think what happened is there was a party and I just went around going, 'Hey, I'll drink some of that and I'll drink some of that...' and I just remember waking up on the bathroom floor, going, 'Where am I?'"
The BBC drama starring Aidan Turner returns to BBC One on September 4th.