Will Smith's memoir appears to shed light on why he smacked comic Chris Rock at the Oscars.
The Men in Black actor, 53, says in his book that being made to feel like a coward is his 'most violent trigger' - after he grew up with an abusive father.
He penned that seeing his dad brutally beaut up his mother when he was just nine-years-old "defined who I am today more than any other moment".
Will explains in the memoir - which sees him call his father a 'violent alcoholic' - that he 'always thought of myself as a coward' for failing to intervene in the beating.
The book - titled Will - was released last November - and it seems to explain why Will went for Chris during Sunday's ceremony.
The famous actor slapped Chris in the face over his joke about wife Jada Pinkett Smith's hair.
Jada, who has alopecia, didn't look impressed at all after Chris told her he was looking forward to seeing her in GI Jane 2 - a role Demi Moore famously shaved her head for.
He then shouted: "Keep my wife's name out of your f***ing mouth" as he returned to the audience.
It appears there is a reason for why Will acted this way - and he traces it back to the moment he watched his father beat up his mother. He felt he had 'failed' to protect her.
According to MailOnline, he wrote in his book: "I saw her spit blood. That moment, in that bedroom, probably more than any other moment, has defined who I am today.
"Within everything I have done since then – the award and accolades, the spotlights and the attention, the characters and the laughs, there has been a subtle string of apologies to my mother for my inaction that day.
"For failing her in that moment. For failing to stand up to my father. For being a coward."
Will also admitted in the book that his father – who he called 'Daddio' – was 'violent, he was an alcoholic' but he was also at every 'game, play or recital'.
He also allegedly wrote that because of his father he always felt 'haunted by an agonising sense that I am failing the women I love'.
