The Government's mantra "education, education, education" is "the most cynical abuse of the word there has ever been", according to Mr Deary, author of the Horrible Histories children's series. "What we're getting today is testing, testing, testing."
When he was a pupil at Fulwell junior school in Sunderland 40 years ago, he had done a trial paper every day. "We were very good at passing tests, he says, "but we weren't prepared for life."
Not until he took part in the school play in his last week at school did he discover he had the ability to be an actor and writer.
Mr Deary was speaking on "Class Act", art of a digital television service for teachers made by Granada in association with The TES and currently being piloted in 10 British schools.
The Government saw children as sponges, to be filled up with the national curriculum and then squeezed at the end of term to find out how much they had learnt, he said. But children arrived at school full of talent, experience, knowledge and skills. It was the teacher's job to find out what was already in the sponge, to extract it and make the most of it.
Mr Deary said Shakespeare would have done badly in the national tests. Hamlet's famous soliloquy in which he muses on whether he should "take up arms against a sea of troubles" would have gained poor marks because it is a mixed metaphor.