Knox spent four years in Capanne prison, outside only one hour a day. She passed time doing sit-ups, writing letters and playing the guitar.
She says her only view to the outside world was a small window looking at a cypress tree, and she could hear women wailing through their cells all day and night.
She says her first friend was a child named Nina, whose mother was a prisoner. But it was the prison chaplain, Don Saulo, whom she says helped her survive.
He taught her how to play the piano on a keyboard she drew on a piece of paper.
She says she spent 1,427 nights in prison for a crime she did not commit.
"I had to grow up in prison for something I did not do," she insists.
She says it was her family her who got her through. She calculated that she saw them one percent of the time, but "they were there 100 percent of the time."
"I felt incredibly guilty for what they were having to sacrifice for me," she said. Her father Curt Knox estimates the family spent more than $1.5 million on legal and travel fees.
Knox drew three columns in her journal ? each one a list of the things she would do with her life based on the three possible outcomes she faced: freedom, 26 years in prison or a life sentence.
Her "life-imprisonment list" included:
Stop writing letters home. Ask family to forget me? Suicide?
While awaiting the court's ruling on her appeal, Knox imagined her mother, Edda Mellas, going home to Seattle alone. Thinking of this worst case scenario -- her mother leaving Italy without her -- she wanted to find a way to comfort her. Knox wrote her mother a letter -- or maybe a goodbye note -- that would arrive after the appeal verdict.
On Oct. 3, 2011, Knox was acquitted of murder and freed immediately. She flew 6,000 miles home to Seattle the next day. Knox's final letter to her mother arrived in Seattle not long after she did.
The beginning reads, "I'm writing this letter in case you come home and I'm not there with you to receive it, just in case we didn't win and I won't be going home for a long time."
Amanda Knox's memoir, "Waiting to be Heard," can be ordered HERE and