"IT'S not the size of the dog in the fight, it's the size of the fight in the dog," - Mark Twain.

After speaking to former Sex Pistols frontman John Lydon, aka Johnny Rotten, this is the phrase that springs to mind.

With the emergence of the punk movement in 1976, Lydon spearheaded the 'last and greatest outbreak of pop-based moral pandemonium' in Britain.

Now living in the USA, Lydon visits the Cheltenham Literature Festival this week to talk about his new book, Anger is an Energy – My Life Uncensored.

From the name of the book, and Lydon’s manic, yet stern picture on the cover, I imagined it would be an irate rant.

But speaking from his home in Los Angeles, he explained that the anger he’s referring to began when he suffered complete memory loss after a bout of life-threatening meningitis aged just seven.

“Anger was the energy that was used to get any kind of memory back at all. It took me quite a few years to fully recover and remember who even my parents were.

"It was the hospital that advised them to ‘keep me angry’, and that would be the energy that I would use to have my memory return, otherwise I could have become complacent.”

“We’re not talking a bitterness here, I was just mad at myself, and somehow or another that energy helped me find the things I needed to find.”

“I think that those energies that are in me explain how I am. And they are testament to the fact that I was a fully fledged human being a long time before the likes of the Malcom McLarens of this world pretended to have invented me.

"The Sex Pistols in many ways did me a great service but a disservice at the same time, because the perception was that it was all a cultivated pop image.

"And it wasn’t, it was just how I was ready to charge into writing songs. I had a lot to resolve with the world.”

“Always in the back of my head is the fear that I won’t wake up and remember who I am again. It’s the most isolated feeling I think you can ever have.

“I could have become institutionalised. I could’ve just gone along with it, taken the easy route and been molly coddled into a world of stupidity.”

“After that, you know what personality is, or what your life force is – it’s a touch and go thing.”

“I was given a second chance and I never said no to it.”

In the wake of The Pistols demise, Lydon went on to form the band Public Image Ltd (PiL), who will be performing a series of UK dates in December.

In the book, he mentions that he finds singing onstage very emotional these days, because of the strong connection he shares with the audience.

“I’ll get these responses, that people are bang in empathy with the point and purpose of the song. They fully understand it and they share it back with me. Now that takes your breath away,” he said.

“I can see the pain that’s being shared there. I can see when somebody’s out there and shares a similar situation. Obviously the details may alter.

"But I can see it in their eyes, and that just triggers me off into, not the darker recesses of my mind, but into areas that need to be opened, need to be exposed to the air, to find resolve.”

“That’s why I’m there. And it’s a joy to behold really, it shows they still have a pulse. The alternative would be like, what? – ‘The hall’s empty tonight, John, everyone’s committed suicide'.”

“We all have an inner anger about something or other, and hopefully we’re all using it to a positive end. I should think the song writing is there for that.”

“I don’t have to be note perfect, I don’t have to be what would qualify as an American Idol special.

"The noises I put together are noises that represent the way I feel, and you don’t have to be a tunesmith for that, you just have to be genuine.”

“I’m trying to express every single emotion that I have ever experienced. And once I let the emotions take over in a gig, songs can shape shift live.

"Some of those songs are, you know, white knuckle stuff for me. Songs like Death Disco, which I wrote about the death of my mother. I never come to grips with the idea of losing anybody, in death.”

“At that point, improvising becomes a roller coaster of a ride. I work with very, very good people in PIL, they’re all highly capable and adaptable, and will take me into areas, with noise and tones and twangs that are really, really challenging for me.

"It’s a very good way we play and perform with each other. When we get bored with the format, we’re capable of leaping into outer space.”

“It’s dreamscape time for me inside music, dreamscape.”

“No holds barred, no rules, it’s the ultimate freedom, I suppose, and it’s the place I like best. It takes so much out of me to get there but it’s worth it. It’s worth it, that’s the trade off.”

*Anger is an Energy: My Life Uncensored is published via Simon & Schuster on Thursday. John Lydon will address Cheltenham Literature Festival on Saturday at 9pm.

For tickets see www.cheltenhamfestivals.com