Sylvester Stallone's memoir will document how he went from "most likely to end up in the electric chair" to a movie legend.

The 78-year-old actor is working on a book with a "brilliant" co-writer and he's planning to go into detail about the drive that made him a Hollywood action hero after being written off at school.

Asked if he's writing a memoir, he told TMZ: "Well you are psychic, my God.

"Yes I am working right now on a novel with a co-writer, whose brilliant, we’re chronicling how this all happened.

"I was least likely, I was voted most likely to end up in the electric chair at school, I shouldn’t be here kind of thing."

The 'Tulsa King' actor recalled how a trip to New York during Woodstock made him realise he needed to do something with his life and gave him the push he needed to move forward as there were so many people around him but he was the only one concerned about his own fate.

He said: "When I arrived in New York it was the day of Woodstock and I was like what is that? The truth is, I walked around, I didn’t know one person, there’s eight million [there] and I was sort of afraid, there’s not one person here who cares a thing about you or ever will so you better do something to survive, go at it because you have zero support team.

"From that moment on, I realised you have to rely very much upon yourself and that hasn't stopped. My biggest fear has turned out to be my biggest successes, trying to overcome them.

"But when I stepped out of that bus station and realised ‘God there’s not one who cares what happens to me so you better care about yourself', that was the beginning of this pursuit."