Will Smith opens up about his abusive father, Willard Carroll Smith Sr., in his upcoming book titled "Will." The actor also reveals he once thought of killing the old man for all the pain he caused his mother, Caroline Bright.

The 53-year-old actor notes in his memoir that his father was a "violent" person but at the same time he was present at every game, play, recital and even movie premiere.

"He was an alcoholic, but he was sober at every premiere of every one of my movies," Smith writes in his book as per People. "He listened to every record. He visited every studio. The same intense perfectionism that terrorized his family put food on the table every night of my life."

Smith then recalls a violent incident involving his father. According to him, when he was 9, he saw his father punch his mother in the head really hard, due to which she lost consciousness.

"I saw her spit blood," he adds. "That moment in that bedroom, probably more than any other moment in my life, has defined who I am."

Smith's parents divorced in 2000 but the actor remained close to his father and cared for him as he dealt with cancer.

The actor shares that one night, as he was taking care of his father and transporting him from one room to another in a wheelchair, his childhood trauma kicked in.

"The path between the two rooms goes past the top of the stairs," he recalls in his book. "As a child I'd always told myself that I would one day avenge my mother. That when I was big enough, when I was strong enough, when I was no longer a coward, I would slay him."

Smith says he paused at the top of the stairs for a moment and thought that he could easily "shove him down" and get away with it.

"As the decades of pain, anger, and resentment coursed then receded, I shook my head and proceeded to wheel Daddio to the bathroom," he writes.

The actor then explains how his childhood trauma has affected his adult life as well as his career.

"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," he notes. "For failing her in the moment. For failing to stand up to my father. For being a coward."

He also reveals that he designed his life to hide from the world and to hide the "coward" by taking the form of a "bigger-than-life movie star."

"What you have come to understand as 'Will Smith,' the alien-annihilating MC, the bigger-than-life movie star, is largely a construction – a carefully crafted and honed character – designed to protect myself," he adds. "To hide myself from the world. To hide the coward."

The actor's father, who used to work as a refrigeration engineer and music promoter, died in 2016 at the age of 76.

Smith's upcoming memoir is slated for release Sunday.

Will Smith
Will Smith at Ciampino Airport on Nov. 17, 2006, in Italy. Giuseppe Cacace/Getty Images