The reason Stephen King can't remember writing one of his most famous books.

Stephen King is one of the best writers in the world.

Over his 50 year career, King has penned more than 87 books, with many of them becoming instant cult favourites.

But he doesn’t remember writing one of his most popular books.

The author, who is now 71, has very little recollection of writing Cujo, a book about a rabid dog who destroys everything in its path.

“There’s one novel, Cujo, that I barely remember writing at all. I don’t say that with pride or shame, only with a vague sense of sorrow and loss. I like that book. I wish I could remember enjoying the good parts as I put them down on the page,” King wrote in his book On Writing.

The IT writer has always spoken openly about his struggle with addiction. Speaking to Emma Brockes at The Guardian in 2013, the author said he first had an inkling that he could be an addict back in 1975 when he was writing The Shining.

“I was drinking, like, a case of beer a night. And I thought, “I’m an alcoholic.” That was probably about ’78, ’79. I thought, “I’ve gotta be really careful, because if somebody says, ‘You’re drinking too much, you have to quit,’ I won’t be able to,” he later told Rolling Stone.

Back then, it was just alcohol. But as he became more and more famous, his addictions escalated.

By the time he wrote Cujo in the early 1980s, King was addicted to cocaine. His cocaine addiction spurred on his writing and vice versa.

“I mean, coke was different from booze. Booze, I could wait, and I didn’t drink or anything. But I used coke all the time,” he explained to Rolling Stone.

Although he doesn’t remember writing the book, the author subconsciously used it to process his own feelings about his addiction. Cujo became one big metaphor about addiction.

The book tells the story of a loyal St Bernard, who becomes infected with rabies after his owners forget to get him vaccinated. Suddenly the innocent, loveable family pet turns into an insatiable killer. He basically becomes a beast whose actions are beyond his own control.

For King the rabies represented fame and the addiction was the monster.

The author has now been sober for decades, since his family staged an intervention in the late 1980s. He often weaves themes of addiction and sobriety into his books.

Although his years of addiction have informed many of his books, King will always regret the time he lost not being present with his family.

“There’s a thing in AA, something they read in a lot of meetings, The Promises. Most of those promises have come true in my life: we’ll come to know a new freedom and new happiness, that’s true. But it also says in there: we will not regret the past nor wish to shut the door on it. And I have no wish to shut the door on the past. I have been pretty upfront about my past. But do I regret? I do. I do. I regret the necessity,” he told The Guardian.