My most memorable recollection has to do with Guantánamo Bay. Orwell probably never heard of the place, but he wrote about it. For some years now, I have played a game when I go to visit my clients there: I take them books and magazines, to see which ones get through the bizarre censors. Jack and the Beanstalk was banned, I never did see why. Runner’s World was banned while Swimming Monthly got in.

Sometimes, the rationale was easy to understand: The Gulag Archipelago was excluded because the military was sensitive about the sobriquet, The Guantánamo Gulag. But The Innocent Man, by John Grisham, was censored, too. Maybe the US military did not like the idea that someone in custody might not be a terrible criminal.

One of the books that I got into the camp for Shaker Aamer was Nineteen Eighty-Four by Orwell. It was, he said, his favourite secular book. “The Torture is for the Torture,” he pronounced, “the System is for the System.” He read it several times over.

We puzzled over how it passed. Surely they saw how it resonated with his experiences in Guantánamo? No, he said, they just did not understand, any more than they had when I brought him Animal Farm, which they likely mistook for an agricultural treatise.

So I asked Aamer to write an educational piece on the book. He took one of the bendy, four-inch ballpoints that are all a detainee is allowed and illustrated why the pen is indeed mightier than the sword. Aamer had arrived in Guantánamo on Valentine’s Day 2002, just as his youngest son, Faris, was born in far-away London. He explained the dystopian world of Nineteen Eighty-Four, as it had been replicated on a US naval base in Cuba 18 years after the book was set. Now, belatedly, enlightened as to Orwell’s meaning, the authorities banned the book. Aamer was eventually released back to Britain in 2015 after 13 years without trial.

• Clive Stafford Smith is founder and director of Reprieve and author of two books shortlisted for the Orwell prize.