The author also suggested that his classroom experiences of the 1940s and 50s - when poetry and words were reduced to exercises in memory, spelling and grammar - are, unfortunately, highly relevant today.
In a declaration handed out at the annual National Association for the Teaching of English conference in Swanwick, Derbyshire, the 60-year-old author of 99 books said that it was his mother who had initially fostered in him a love of words and stories.
She would read to him every night children's literature ranging from Winnie the Pooh to poems by Shakespeare and Kipling's Just So Stories.
But everything changed when he started at primary school in London, followed by prep school in Sussex, and then King's School in Canterbury.
He said: "Suddenly it was school. Words were exercises. They had to be written right, punctuated right. Fear crept into words and darkened them for me.
"At senior school... I found that stories had become mere texts, to slice up into little pieces, to analyse, to criticise.
"No Shakespeare play touched me, no Hardy novel, no Dickens novel. I read them because I had to - because I was going to be tested on them."
He did, however, take up a place at King's College, London, to read English and French, but it was not until he stumbled upon Sir Gawain and the Green Knight, the anonymously penned 14th-century poem, that the love affair was rekindled. "I was entranced again - as once I had been when my mother had read me the Just So Stories," he said.
Mr Morpurgo, who spent eight years as a primary teacher, has been an outspoken critic of the culture of testing.
Expecting children to come up with a creative piece of work in 45 minutes, as they were required to in key stage 2 tests, is largely pointless, he believes, and is a practice which tends to favour those with "slick brains" rather than the truly creative.
Mr Morpurgo added: "Let's give space to teachers to teach, to children to learn.
"Yes, children must write and spell and punctuate properly - but fear creates inhibition and resentment. It must be a love of literature first."
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