Will Smith reveals he once considered killing his dad to 'avenge' his mother

• Will Smith revealed he once considered killing his father, according to an excerpt from his upcoming memoir obtained by People.
• Smith wrote that when he was a child, he witnessed his dad "punch [his] mother in the side of the head so hard that she collapsed."

Will Smith has revealed that he once contemplated killing his father to avenge the abuse his mother suffered during his childhood.

In an exclusive excerpt from his upcoming memoir "Will" obtained by People, Smith discussed his complicated relationship with his father, William Carroll Smith Sr.

"My father was violent, but he was also at every game, play, and recital. He was an alcoholic, but he was sober at every premiere of every one of my movies," Smith wrote.

He then recalled a violent moment he witnessed between his mother and father that would haunt him for years to come.

"When I was nine years old, I watched my father punch my mother in the side of the head so hard that she collapsed. I saw her spit blood. That moment in that bedroom, probably more than any other moment in my life, has defined who I am," he wrote.

"Within everything that I have done since then - the awards and accolades, the spotlights and 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 the moment. For failing to stand up to my father. For being a coward," he continued.

With that moment in mind, he wrote that he swore he would avenge his mother one day. That day almost came when Smith was caring for his father, who had cancer, decades later.

"One night, as I delicately wheeled him from his bedroom toward the bathroom, a darkness arose within me ... I paused at the top of the stairs. I could shove him down, and easily get away with it," he wrote. "As the decades of pain, anger, and resentment coursed then receded, I shook my head and proceeded to wheel Daddio to the bathroom."

Instead, he channeled that anger into insight: "There is nothing that you can receive from the material world that will create inner peace or fulfillment," he said. "In the end, it will not matter one single bit how well [people] loved you - you will only gain 'the Smile' based on how well you loved them."

Smith's parents divorced in 2000 and Will Sr. later died in 2016.

Smith has been forthcoming about his mental health this year; in his upcoming docuseries "Will Smith: The Best Shape of My Life," he said he once considered suicide.