Cleared murder suspect Amanda Knox has revealed she had an 'epiphany' during her time in prison as she reflected on other 'realities' in which she could have been killed or committed suicide.

Knox, who was acquitted over the 2007 killing of her roommate Meredith Kercher due to a lack of evidence, posted a bizarre Twitter thread on Friday detailing how she came to terms with her initial conviction. 

The 35-year-old lamented being 'locked away for the best years of my life' and 'deprived of opportunities' - labelling her life 'small, cruel, sad and unfair. 

But Knox, dubbed 'Foxy Knoxy' by the tabloid press, said she suddenly realized she had to stop 'waiting' for her life to start and accept her sentence quietly by finding joy through sit-ups, writing letters and reading.

She went on to say she considered 'alternate realities' in prison about her being murdered instead of Meredith and another in which she killed herself. 

She wrote: 'What if I had been home that night, not Meredith, and Rudy Guede had killed me instead?

'What if I was acquitted and freed in five years? In ten?

What if I served my entire sentence, and came home in my late 40s, a barren, bereft woman? What if I killed myself…'

She said she examined these thoughts in 'vivid detail,' - a process stopped them from 'creeping' into her nightmares.

But Knox revealed her 'emotional default setting remained firmly stuck on sad,' during her time in prison adding 'I woke up sad, spent the entire day sad and went to sleep sad.'

However she found meaning through 'sit-ups, walking laps, writing a letter, reading a book.'

'I was slowly and deliberately walking a tightrope across a bottomless foggy abyss,' she wrote.

'In many ways, though I’m now free, legally vindicated, a woman with a career in the arts (as I’d always dreamed), an advocate for justice (which I never dreamed), a wife with a loving husband, a mother with a joyous child...I’m still walking that tightrope,' she added.

Knox signed off the thread with a photograph of herself smiling in prison, writing: 'Everyone is going through something even when they're smiling.'

Many Twitter users heaped praise on Knox's 'insightful' thread - though others accused her of self-obsession.

On user wrote: 'And yet it's still ALL about you. Please go away and be quiet! A daughter and sister was murdered and she is the most important person in this horrific event, not you.'

Leeds University student Meredith, 21, was found stabbed to death with her throat slashed in her bedroom of the apartment she shared with Knox in the Italian hilltop town of Perugia.