Harvey's reaction to his dementia is not what you might expect. 'I'm so happy,' he says. 'I wouldn't reverse it for anything.'
Harvey has a relatively rare dementia called posterior cortical atrophy or PCA, a variant of Alzheimer's disease. Inasmuch as he has difficulty remembering things and can't do basic arithmetic, his condition conforms to the stereotype of dementia. But PCA particularly affects spatial awareness: it can lead to disorientation, visual illusions, and problems with making your movements coincide with your perception of space. Harvey has trouble with vests; another person with PCA recounts how, aiming to sit in an empty seat, he found himself instead in his vicar's lap. But for Harvey, who is 78, these are just inconveniences in a wonderful life. He has never, he says, felt so full of love for his wife, Diana, who confirms that his expressions of affection are much more frequent now than before his PCA developed.